Pakati pa oxides sanali siliceous, aluminiyamu ali katundu makina, kutentha kukana ndi dzimbiri kukana, pamene mesoporous aluminiyamu (MA) ali chosinthika pore kukula, lalikulu enieni pamwamba, lalikulu pore voliyumu ndi otsika mtengo kupanga, amene ankagwiritsa ntchito catalysis, kulamulidwa kwa mankhwala osokoneza bongo, kulengeza ndi madera ena, monga ming'alu, hydrocracking ndi hydrodesulfurization ya petroleum raw materials.Microporous alumina imagwiritsidwa ntchito kwambiri m'makampani, koma idzakhudza mwachindunji ntchito ya alumina, moyo wautumiki ndi kusankha kwa chothandizira. Mwachitsanzo, poyeretsa utsi wagalimoto, zowononga zomwe zimayikidwa kuchokera ku zowonjezera zamafuta a injini zimapanga coke, zomwe zingayambitse kutsekeka kwa pores chothandizira, motero kuchepetsa ntchito ya chothandizira. Surfactant ingagwiritsidwe ntchito kusintha mawonekedwe a chonyamulira cha alumina kuti apange MA. Sinthani magwiridwe antchito ake othandizira.
MA imakhala ndi zoletsa, ndipo zitsulo zogwira ntchito zimazimitsidwa pambuyo powerengera kutentha kwambiri. Komanso, pambuyo mkulu-kutentha calcination, dongosolo mesoporous kugwa, MA mafupa ali mu amorphous boma, ndi acidity pamwamba sangathe kukwaniritsa zofunika m'munda wa functionalization. Chithandizo chosinthidwa nthawi zambiri chimafunika kuti ntchito yothandiza, kusasunthika kwa mesoporous, kukhazikika kwa kutentha komanso acidity ya pamwamba pa zinthu za MA.Magulu osintha odziwika bwino amaphatikiza ma heteroatom achitsulo (Fe, Co, Ni, Cu, Zn, Pd, Pt, Zr, etc. ) ndi ma oxides achitsulo (TiO2, NiO, Co3O4, CuO, Cu2O, RE2O7, ndi zina zotero) Zokwezedwa pamwamba pa MA kapena kulowetsedwa mu chigoba.
Kukonzekera kwapadera kwa ma elekitironi kwa zinthu zomwe sizikusowa padziko lapansi kumapangitsa kuti mankhwala ake akhale ndi mawonekedwe apadera a kuwala, magetsi ndi maginito, ndipo amagwiritsidwa ntchito muzinthu zothandizira, zipangizo za photoelectric, adsorption materials ndi maginito. Osowa lapansi kusinthidwa zipangizo mesoporous akhoza kusintha asidi (alkali) katundu, kuonjezera ntchito mpweya, ndi lithe zitsulo nanocrystalline chothandizira ndi kubalalitsidwa yunifolomu ndi khola nanometer scale.Appropriate porous zipangizo ndi osowa lapansi akhoza kusintha padziko kubalalitsidwa kwa zitsulo nanocrystals ndi bata ndi mpweya mafunsidwe kukana catalysts. Mu pepalali, kusinthidwa kosowa kwa dziko lapansi ndi magwiridwe antchito a MA kudzayambitsidwa kuti apititse patsogolo magwiridwe antchito, kukhazikika kwamafuta, mphamvu yosungira mpweya, malo enieni komanso mawonekedwe a pore.
1 MA kukonzekera
1.1 Kukonzekera kwa chonyamulira alumina
Njira yokonzekera ya chonyamulira cha alumina imatsimikizira kugawa kwake kwa pore, ndipo njira zake zokonzekera zodziwika bwino zimaphatikizapo pseudo-boehmite (PB) njira yowonongeka ndi njira ya sol-gel. Pseudoboehmite (PB) adafunsidwa koyamba ndi Calvet, ndipo H + adalimbikitsa peptization kuti apeze γ-AlOOH colloidal PB yomwe ili ndi madzi osakanikirana, omwe amapangidwa ndi madzi otentha kwambiri kuti apange alumina. Malingana ndi zipangizo zosiyanasiyana, nthawi zambiri zimagawidwa mu njira ya mpweya, njira ya carbonization ndi alcoholaluminium hydrolysis method.The colloidal solubility ya PB imakhudzidwa ndi crystallinity, ndipo imakongoletsedwa ndi kuwonjezeka kwa crystallinity, ndipo imakhudzidwanso ndi magawo opangira ntchito.
PB nthawi zambiri imakonzedwa ndi njira yamvula. Alkali ndi anawonjezera mu njira aluminiyamu kapena asidi anawonjezera mu njira aluminiyamu ndi mpweya kupeza hydrated aluminiyamu (alkali mpweya), kapena asidi anawonjezera mu aluminiyamu mpweya kupeza alumina monohydrate, amene ndiye osambitsidwa, zouma ndi calcined kupeza PB. Mpweya wa mpweya ndi wosavuta kugwiritsa ntchito komanso wotsika mtengo, womwe umagwiritsidwa ntchito nthawi zambiri popanga mafakitale, koma umakhudzidwa ndi zinthu zambiri (njira pH, ndende, kutentha, etc.) . Mu njira ya carbonization, Al (OH) 3 imapezedwa ndi CO2 ndi NaAlO2, ndipo PB ikhoza kupezeka pambuyo pokalamba. Njirayi ili ndi ubwino wa ntchito yosavuta, khalidwe lapamwamba la mankhwala, palibe kuipitsidwa ndi mtengo wotsika, ndipo akhoza kukonzekera alumina ndi ntchito yothandiza kwambiri, kukana kwa dzimbiri komanso malo apamwamba kwambiri omwe ali ndi ndalama zochepa komanso njira yobwerera.Aluminiyamu ya alkoxide hydrolysis imagwiritsidwa ntchito nthawi zambiri. kukonzekera PB yoyera kwambiri. Aluminiyamu alkoxide ndi hydrolyzed kupanga zotayidwa okusayidi monohydrate, ndiyeno ankachitira kupeza mkulu chiyero PB, amene ali wabwino crystallinity, yunifolomu tinthu kukula, anaikira pore kukula kugawa ndi mkulu umphumphu wa ozungulira particles. Komabe, njirayi ndi yovuta, ndipo n'zovuta kuchira chifukwa chogwiritsa ntchito mankhwala osungunulira a poizoni.
Komanso, mchere wamchere kapena mankhwala organic zitsulo amagwiritsidwa ntchito pokonzekera aluminiyamu precursors ndi Sol-gel osakaniza njira, ndi madzi oyera kapena zosungunulira organic anawonjezera kukonzekera njira kupanga sol, amene ndiye gelled, zouma ndi wokazinga. Pakali pano, ndondomeko yokonza alumina akadali bwino pamaziko a PB madzi m'thupi njira, ndi carbonization njira wakhala njira yaikulu kwa mafakitale aluminiyamu kupanga chifukwa cha chuma chake ndi chilengedwe protection.Alumina wokonzedwa ndi Sol-gel osakaniza njira wakopa chidwi kwambiri. chifukwa cha kukula kwake kofananako, yomwe ndi njira yotheka, koma iyenera kukonzedwa kuti ikwaniritse ntchito zamakampani.
1.2 MA kukonzekera
aluminiyamu ochiritsira sangathe kukwaniritsa zofunika ntchito, choncho m'pofunika kukonzekera mkulu-ntchito MA. The kaphatikizidwe njira zambiri monga: nano-casting njira ndi carbon nkhungu monga cholimba template; Kaphatikizidwe ka SDA: Evaporation-induced self-assembly process (EISA) pamaso pa ma tempuleti ofewa monga SDA ndi ma cationic, anionic kapena nonionic surfactants.
1.2.1 Njira ya EISA
Template yofewa imagwiritsidwa ntchito mu acidic acid, yomwe imapewa zovuta komanso zowononga nthawi ya njira yolimba ya membrane ndipo imatha kuzindikira kusinthasintha kosalekeza kwa kabowo. Kukonzekera kwa MA ndi EISA kwakopa chidwi kwambiri chifukwa cha kupezeka kwake kosavuta komanso kuberekana. Mitundu yosiyanasiyana ya mesoporous imatha kukonzedwa. Pore kukula MA akhoza kusinthidwa ndi kusintha hydrophobic unyolo kutalika surfactant kapena kusintha molar chiŵerengero cha hydrolysis chothandizira kuti aluminiyamu kalambulabwalo mu solution.Choncho, EISA, amatchedwanso sitepe imodzi kaphatikizidwe ndi kusinthidwa Sol-gel osakaniza njira pamwamba pamwamba. dera MA ndipo analamula mesoporous alumina (OMA), wakhala ntchito zosiyanasiyana zofewa zidindo, monga P123, F127, triethanolamine (tiyi), etc. EISA akhoza m'malo Co-msonkhano ndondomeko ya organoaluminium precursors, monga zotayidwa alkoxides ndi surfactant zidindo , kawirikawiri aluminium isopropoxide ndi P123, popereka ma mesoporous materials.Kukula bwino kwa ndondomeko ya EISA kumafuna kusintha kolondola kwa hydrolysis ndi condensation kinetics kuti apeze sol yokhazikika ndi kulola kukula kwa mesophase opangidwa ndi surfactant micelles mu sol.
Mu ndondomeko ya EISA, kugwiritsa ntchito zosungunulira zopanda madzi (monga ethanol) ndi organic complexing agents zitha kuchedwetsa bwino hydrolysis ndi condensation rate ya organoaluminium precursors ndikupangitsa kudziphatikiza kwa zida za OMA, monga Al(OR)3ndi aluminium isopropoxide. Komabe, mu zosungunulira zosakhala zamadzimadzi, zosungunulira zamadzimadzi nthawi zambiri zimataya hydrophilicity/hydrophobicity. Kuphatikiza apo, chifukwa cha kuchedwa kwa hydrolysis ndi polycondensation, mankhwala apakatikati ali ndi gulu la hydrophobic, zomwe zimapangitsa kuti zikhale zovuta kulumikizana ndi template ya surfactant. Pokhapokha pamene ndende ya surfactant ndi digiri ya hydrolysis ndi polycondensation wa zotayidwa pang'onopang'ono kuchuluka m`kati zosungunulira evaporation akhoza kudziona gulu Chinsinsi ndi zotayidwa zichitike. Choncho, magawo ambiri amene amakhudza zinthu evaporation wa solvents ndi hydrolysis ndi condensation anachita wa precursors, monga kutentha, chinyezi wachibale, chothandizira, zosungunulira evaporation mlingo, etc., zingakhudze chomaliza dongosolo msonkhano. Monga momwe tawonetsera mkuyu. 1, zida za OMA zokhala ndi kukhazikika kwamafuta komanso magwiridwe antchito apamwamba zidapangidwa ndi solvothermal assisted evaporation induced self-assembly (SA-EISA). solvothermal mankhwala kulimbikitsa wathunthu hydrolysis wa zolozera zotayidwa kupanga ang'onoang'ono masango zitsulo zotayidwa hydroxyl magulu, amene patsogolo kugwirizana pakati surfactants ndi aluminiyamu. Mwachikhalidwe cha EISA, njira ya evaporation imatsagana ndi hydrolysis ya organoaluminium precursor, kotero mikhalidwe ya evaporation imakhala ndi chikoka chofunikira pamachitidwe ndi kapangidwe komaliza kwa OMA. The solvothermal mankhwala sitepe amalimbikitsa wathunthu hydrolysis wa zotayidwa kalambulabwalo ndipo amapanga pang'ono condensed zotayidwa hydroxyl magulu.OMA aumbike pansi pa zinthu zosiyanasiyana evaporation. Poyerekeza ndi MA yokonzedwa ndi njira yachikhalidwe ya EISA, OMA yokonzedwa ndi njira ya SA-EISA ili ndi voliyumu ya pore yapamwamba, malo enieni enieni komanso kukhazikika kwamafuta. M'tsogolomu, EISA njira angagwiritsidwe ntchito kukonzekera kopitilira muyeso-lalikulu kabowo MA ndi mkulu kutembenuka mlingo ndi selectivity kwambiri popanda kugwiritsa ntchito reming wothandizira.
Chithunzi cha 1 tchati choyendera cha njira ya SA-EISA yopangira zida za OMA
1.2.2 njira zina
Kukonzekera kokhazikika kwa MA kumafuna kuwongolera koyenera kwa magawo ophatikizika kuti akwaniritse mawonekedwe owoneka bwino a mesoporous, komanso kuchotsa zida za template ndizovuta, zomwe zimasokoneza kaphatikizidwe kake. Pakalipano, zolemba zambiri zanena za kuphatikizika kwa MA ndi ma templates osiyanasiyana. M'zaka zaposachedwa, kafukufukuyu adayang'ana kwambiri kaphatikizidwe ka MA ndi shuga, sucrose ndi wowuma monga ma templates ndi aluminium isopropoxide mu aqueous solution.Zambiri mwazinthu za MA izi zimapangidwa kuchokera ku aluminium nitrate, sulfate ndi alkoxide monga magwero a aluminiyamu. MA CTAB imapezekanso mwakusintha mwachindunji kwa PB ngati gwero la aluminiyamu. MA yokhala ndi mawonekedwe osiyanasiyana, mwachitsanzo, Al2O3) -1, Al2O3)-2 ndi al2o3Ndipo imakhala yabwino kukhazikika kwamafuta. Kuphatikizika kwa surfactant sikumasintha mawonekedwe a kristalo a PB, koma amasintha mawonekedwe a tinthu tating'onoting'ono. Komanso, mapangidwe Al2O3-3 aumbike ndi adhesion wa nanoparticles okhazikika ndi organic zosungunulira msomali kapena aggregation kuzungulira PEG. Komabe, kukula kwa pore kwa Al2O3-1 ndikocheperako. Kuphatikiza apo, zida zopangira palladium zidakonzedwa ndi zopangira MA monga chonyamulira.Mu kuyaka kwa methane, chothandizira chothandizidwa ndi Al2O3-3 chinawonetsa ntchito yabwino yothandizira.
Kwa nthawi yoyamba, MA yokhala ndi kukula kwa pore yopapatiza idakonzedwa pogwiritsa ntchito zotsika mtengo komanso zolemera kwambiri za aluminiyamu wakuda slag ABD. Kupanga kumaphatikizapo ndondomeko yochotsa pa kutentha kochepa komanso kuthamanga kwabwino. The particles olimba otsala mu ndondomeko m'zigawo sadzakhala kuipitsa chilengedwe, ndipo akhoza ataunjikidwa ndi otsika chiopsezo kapena reus ngati filler kapena aggregate mu ntchito konkire. Malo enieni a MA opangidwa ndi 123 ~ 162m2 / g, Kugawa kwa pore ndikopapatiza, utali wa nsonga ndi 5.3nm, ndipo porosity ndi 0.37 cm3 / g. Zomwe zili ndi nano-size ndipo kukula kwa kristalo ndi pafupifupi 11nm. Solid-state synthesis ndi njira yatsopano yopangira MA, yomwe ingagwiritsidwe ntchito popanga ma radiochemical absorbent kuti agwiritsidwe ntchito pachipatala. Aluminiyamu chloride, ammonium carbonate ndi glucose zopangira zopangira zimasakanizidwa mu chiŵerengero cha molar cha 1: 1.5: 1.5, ndipo MA imapangidwa ndi njira yatsopano yolimba ya mechanochemical reaction. %.
Kufotokozera mwachidule, m'tsogolomu, ma templates ang'onoang'ono a maselo amathanso kupangidwa kuti amange mapangidwe a pore omwe amapangidwa ndi magulu osiyanasiyana, kusintha bwino mapangidwe, maonekedwe ndi maonekedwe a mankhwala a zinthu, ndikupanga malo akuluakulu padziko lapansi ndikulamula wormhole MA. Onani ma templates otsika mtengo ndi magwero a aluminiyamu, konzani kaphatikizidwe, fotokozani kaphatikizidwe kaphatikizidwe ndikuwongolera njirayo.
Njira yosinthira 2 MA
Njira zogawira mofanana zigawo zogwira ntchito pa MA chonyamulira zikuphatikizapo impregnation, in-situ synthe-sis, mpweya, kusinthana kwa ion, kusakaniza kwa makina ndi kusungunuka, pakati pa zomwe ziwiri zoyambirira zimagwiritsidwa ntchito kwambiri.
2.1 in-situ synthesis njira
Magulu omwe amagwiritsidwa ntchito posintha magwiridwe antchito amawonjezeredwa pokonzekera MA kuti asinthe ndikukhazikika kwa mafupa azinthu ndikuwongolera magwiridwe antchito othandizira. Njirayi ikuwonetsedwa mu Chithunzi 2. Liu et al. adapanga Ni/Mo-Al2O3in situ ndi P123 ngati template. Onse a Ni ndi Mo adabalalitsidwa m'njira zoyendetsedwa ndi MA, osawononga mawonekedwe a mesoporous a MA, ndipo magwiridwe antchito adachita bwino. Kutengera njira yakukulira mu-situ pa gamma-al2o3substrate yopangidwa, Poyerekeza ndi γ-Al2O3, MnO2-Al2O3 ili ndi malo okulirapo a BET apamtunda ndi pore voliyumu, ndipo ili ndi mawonekedwe a bimodal mesoporous okhala ndi kagayidwe kakang'ono ka pore. MnO2-Al2O3 ili ndi kutsatsa kwachangu komanso kuchita bwino kwambiri kwa F-, ndipo ili ndi mitundu yambiri ya pH yogwiritsira ntchito (pH=4~10), yomwe ndi yoyenera pakugwiritsa ntchito mafakitale. Ntchito yobwezeretsanso ya MnO2-Al2O3 ndiyabwino kuposa ya γ-Al2O.Structural bata ikuyenera kukonzedwanso. Mwachidule, zinthu zosinthidwa za MA zomwe zimapezedwa ndi kaphatikizidwe ka in-situ zili ndi dongosolo labwino, kulumikizana mwamphamvu pakati pamagulu ndi zonyamulira alumina, kuphatikiza kolimba, katundu wamkulu wazinthu, ndipo sizosavuta kuyambitsa kukhetsa kwa zigawo zogwira munjira yothandizira. , ndipo magwiridwe antchito amawongoleredwa bwino kwambiri.
Mkuyu. 2 Kukonzekera MA functionalized ndi mu-situ kaphatikizidwe
2.2 njira yoberekera
Kumiza MA okonzeka mu gulu losinthidwa, ndikupeza MA zosinthidwa pambuyo pa chithandizo, kuti azindikire zotsatira za catalysis, adsorption ndi zina zotero. Cai et al. anakonza MA kuchokera P123 ndi sol-gel osakaniza njira, ndi ankawaviika Mowa ndi tetraethylenepentamine njira kupeza amino kusinthidwa MA zakuthupi ndi amphamvu adsorption ntchito. Komanso, Belkacemi et al. choviikidwa mu ZnCl2solution ndi ndondomeko yomweyo kupeza analamula zinki doped kusinthidwa MA materials.Magawo enieni pamwamba ndi pore voliyumu ndi 394m2/g ndi 0.55 cm3/g, motero. Poyerekeza ndi in-situ kaphatikizidwe njira, inpregnation njira ali bwino element kubalalitsidwa, khola mesoporous kapangidwe ndi zabwino adsorption ntchito, koma mphamvu yolumikizana pakati pa zigawo yogwira ndi chonyamulira aluminiyamu ndi chofooka, ndi chothandizira ntchito mosavuta kusokonezedwa ndi zinthu zakunja.
3 ntchito kupita patsogolo
Kaphatikizidwe ka rare Earth MA yokhala ndi zinthu zapadera ndizomwe zikuchitika m'tsogolomu. Pakali pano, pali njira zambiri kaphatikizidwe. Magawo azinthu amakhudza magwiridwe antchito a MA. Malo enieni, voliyumu ya pore ndi ma pore awiri a MA amatha kusinthidwa ndi mtundu wa template ndi kapangidwe ka aluminium kalambulabwalo. Kutentha kwa calcination ndi ndende ya template ya polima kumakhudza malo enieni komanso pore voliyumu ya MA. Suzuki ndi Yamauchi adapeza kuti kutentha kwa calcination kunawonjezeka kuchokera ku 500 ℃ kufika ku 900 ℃. Kutsekerako kungathe kuwonjezereka ndipo pamwamba pake akhoza kuchepetsedwa. Kuonjezera apo, chithandizo chosowa chosintha dziko lapansi chimapangitsa kuti ntchitoyo ikhale yabwino, kukhazikika kwa kutentha kwapamwamba, kukhazikika kwapangidwe ndi acidity ya pamwamba ya MA zipangizo mu njira yothandizira, ndipo imakumana ndi chitukuko cha MA functionalization.
3.1 Defluorination Adsorbent
Fluorine m'madzi akumwa ku China ndi yovulaza kwambiri. Kuphatikiza apo, kuchuluka kwa fluorine m'mafakitale zinc sulphate solution kungayambitse dzimbiri la mbale ya elekitirodi, kuwonongeka kwa malo ogwirira ntchito, kuchepa kwa mphamvu ya zinki yamagetsi komanso kuchepa kwa madzi obwezerezedwanso mu dongosolo lopanga asidi. ndi electrolysis ndondomeko ya fluidized bedi ng'anjo Kuwotcha flue mpweya. Pakalipano, njira ya adsorption ndi yokongola kwambiri pakati pa njira zodziwika bwino za defluorination yonyowa. Adamulowetsa mpweya, amorphous aluminiyamu, adamulowetsa aluminiyamu ndi adsorbents ena akhala ntchito defluorination madzi, koma mtengo wa adsorbents ndi mkulu, ndi adsorption mphamvu ya F-mu ndale njira kapena mkulu ndende ndi low.Activated aluminiyamu wakhala ambiri ambiri ambiri. adaphunzira adsorbent yochotsa fluoride chifukwa cha kuyanjana kwake kwakukulu komanso kusankha kwa fluoride pamtengo wa pH wa ndale, koma imachepetsedwa ndi kuchepa kwa mphamvu ya fluoride, ndipo pa pH <6 yokha imatha kukhala ndi ntchito yabwino ya fluoride adsorption.MA yakopa chidwi chambiri. pakuwongolera kuwononga chilengedwe chifukwa cha malo ake akuluakulu, kukula kwake kwa pore, magwiridwe antchito a acid-base, kukhazikika kwamafuta ndi makina. Kundu et al. anakonza MA ndi pazipita fluorine adsorption mphamvu 62.5 mg/g. Mphamvu ya fluorine adsorption ya MA imakhudzidwa kwambiri ndi maonekedwe ake, monga malo enieni, magulu ogwira ntchito pamtunda, kukula kwa pore ndi kukula kwa pore.
Chifukwa cha asidi olimba a La komanso kulimba kwa fluorine, pali mgwirizano wamphamvu pakati pa La ndi ayoni a fluorine. M'zaka zaposachedwa, kafukufuku wina wapeza kuti La monga chosinthira amatha kupititsa patsogolo mphamvu ya adsorption ya fluoride. Komabe, chifukwa cha kukhazikika kwapang'onopang'ono kwa ma adsorbents osowa padziko lapansi, maiko osowa kwambiri amalowetsedwa mu yankho, zomwe zimapangitsa kuipitsidwa kwamadzi kwachiwiri ndikuwononga thanzi la anthu. Kumbali inayi, kuchuluka kwa aluminiyumu m'madzi ndi chimodzi mwazinthu zomwe zimakhudza thanzi la munthu. Choncho, m`pofunika kukonzekera mtundu wa gulu adsorbent ndi kukhazikika bwino ndipo palibe leaching kapena zochepa leaching wa zinthu zina mu fulorini kuchotsa ndondomeko. MA yosinthidwa ndi La ndi Ce idakonzedwa ndi njira ya impregnation (La/MA ndi Ce/MA). Ma oxides osowa padziko lapansi adakwezedwa bwino pa MA pamwamba kwa nthawi yoyamba, yomwe inali ndi magwiridwe antchito apamwamba kwambiri. Njira zazikulu zochotsera fulorini ndi ma electrostatic adsorption ndi ma adsorption amankhwala, kukopa kwa ma elekitironi kwa charger yabwino komanso kusinthana kwa ligand kumaphatikiza ndi hydroxyl, the hydroxyl zinchito gulu pa adsorbent pamwamba amapanga hydrogen chomangira ndi F-, kusinthidwa kwa La ndi Ce bwino adsorption mphamvu fluorine, La/MA lili zambiri hydroxyl adsorption malo, ndi mphamvu adsorption F ndi dongosolo la La/MA. >Ce/MA>MA. Ndi kuchulukitsidwa kwa ndende yoyambirira, mphamvu yotsatsa ya fluorine imawonjezeka. Kutsatsa kwabwino kumakhala bwino pamene pH ili 5 ~ 9, ndipo njira yotsatsira ya fluorine imagwirizana ndi Langmuir isothermal adsorption model. Kuphatikiza apo, zonyansa za ayoni za sulphate mu alumina zitha kukhudzanso kwambiri zitsanzo. Ngakhale kuti kafukufuku wokhudzana ndi osowa padziko lapansi osinthidwa alumina wachitika, kafukufuku wambiri amayang'ana njira ya adsorbent, yomwe imakhala yovuta kugwiritsidwa ntchito m'mafakitale. ndi kusamuka makhalidwe a ayoni fluorine, kupeza kothandiza, otsika mtengo ndi zongowonjezwdwa fluorine ayoni adsorbent kwa defluorination zinki sulfate njira mu zinki hydrometallurgy dongosolo, ndi kukhazikitsa ndondomeko ulamuliro chitsanzo kuchitira mkulu fluorine njira zochokera osowa lapansi MA nano adsorbent.
3.2 Catalyst
3.2.1 Kusintha kowuma kwa methane
Dziko lapansi losowa limatha kusintha ma acidity (maziko) azinthu za porous, kuonjezera mwayi wa okosijeni, ndikupanga zopangira ndi kubalalitsidwa yunifolomu, sikelo ya nanometer komanso kukhazikika. Nthawi zambiri amagwiritsidwa ntchito kuthandizira zitsulo zolemekezeka ndi zitsulo zosinthika kuti zithandizire kutulutsa kwa CO2. Pakali pano, osowa nthaka kusinthidwa mesoporous zipangizo zikukula kwa methane dry reforming (MDR), photocatalytic kuwonongeka kwa VOCs ndi kuyeretsa mpweya mchira. Poyerekeza ndi zitsulo wolemekezeka (monga Pd, Ru, Rh, etc.) ndi zitsulo zina kusintha (monga Co, Fe, etc.), Ni/Al2O3catalyst imagwiritsidwa ntchito kwambiri pakuchita kwake kothandizira kwambiri komanso kusankha, kukhazikika kwakukulu komanso mtengo wotsika wa methane. Komabe, sintering ndi mpweya mafunsidwe a Ni nanoparticles padziko Ni/Al2O3 kutsogolera kwa deactivation mofulumira wa chothandizira. Choncho, m'pofunika kuwonjezera mofulumira, kusintha chonyamulira chothandizira ndi kukonza njira yokonzekera kuti mupititse patsogolo ntchito zothandizira, kukhazikika ndi kukana kutentha. Nthawi zambiri, osowa dziko oxides angagwiritsidwe ntchito monga olimbikitsa structural ndi pakompyuta mu heterogeneous catalysts, ndi CeO2 bwino kubalalitsidwa kwa Ni ndi kusintha katundu wa zitsulo Ni mwa amphamvu zitsulo thandizo mogwirizana.
MA amagwiritsidwa ntchito kwambiri kupititsa patsogolo kufalikira kwa zitsulo, komanso kuletsa zitsulo zogwira ntchito kuti zisagwirizane. La2O3 yokhala ndi mphamvu yosungiramo okosijeni yayikulu imathandizira kukana kwa kaboni pakutembenuka, ndipo La2O3 imathandizira kubalalitsidwa kwa Co pa mesoporous alumina, yomwe ili ndi ntchito yosintha kwambiri komanso kulimba mtima. La2O3promoter imawonjezera ntchito ya MDR ya Co/MA catalyst, ndipo Co3O4and CoAl2O4phases amapangidwa pa chothandizira pamwamba. Mu ndondomeko ya MDR, kuyanjana kwa in-situ pakati pa La2O3 ndi CO2formed La2O2CO3mesophase, zomwe zinapangitsa kuti CxHy athetsedwe bwino pamtunda wothandizira. La2O3 imalimbikitsa kuchepetsedwa kwa haidrojeni popereka kusachulukira kwa ma elekitironi apamwamba komanso kukulitsa mwayi wa okosijeni mu 10% Co/MA. Kuphatikiza kwa La2O3 kumachepetsa mphamvu yowonekera ya CH4consumption. Choncho, kutembenuka kwa CH4kuwonjezeka kufika pa 93.7% pa 1073K K. Kuwonjezera kwa La2O3 kunapititsa patsogolo ntchito yothandizira, kulimbikitsa kuchepetsa H2, kuonjezera chiwerengero cha malo ogwirira ntchito a Co0, kutulutsa mpweya wocheperako ndikuwonjezera mwayi wa okosijeni kufika 73.3%.
Ce ndi Pr adathandizidwa pa Ni/Al2O3catalyst ndi njira yofananira yoyimba mu Li Xiaofeng. Pambuyo powonjezera Ce ndi Pr, kusankha kwa H2kuwonjezeka komanso kusankha kwa CO kunachepa. MDR yosinthidwa ndi Pr inali ndi luso lothandizira kwambiri, ndipo kusankha kwa H2kunawonjezeka kuchokera ku 64.5% mpaka 75.6%, pamene kusankha kwa CO kunatsika kuchokera ku 31.4% Peng Shujing et al. ntchito Sol-gel osakaniza njira, Ce-zosinthidwa MA linakonzedwa ndi aluminium isopropoxide, isopropanol zosungunulira ndi cerium nitrate hexahydrate. Malo enieni a mankhwalawo adawonjezeka pang'ono. Kuwonjezera kwa Ce kunachepetsa kuphatikizika kwa nanoparticles ngati ndodo pa MA pamwamba. Magulu ena a hydroxyl pamtunda wa γ- Al2O3 anali ataphimbidwa ndi mankhwala a Ce. Kukhazikika kwa kutentha kwa MA kunasinthidwa, ndipo palibe kusintha kwa kristalo komwe kunachitika pambuyo pa calcination pa 1000 ℃ kwa maola 10. Wang Baowei et al. okonzeka MA zinthu CeO2-Al2O4by coprecipitation njira. CeO2 yokhala ndi timbewu tating'ono tating'ono tating'ono tating'ono tating'ono tomwe timamwazikana mu alumina. Pambuyo pothandizira Co ndi Mo pa CeO2-Al2O4, kuyanjana pakati pa alumina ndi gawo logwira ntchito Co ndi Mo kudalepheretsedwa ndi CEO2.
Othandizira osowa padziko lapansi (La, Ce, y ndi Sm) akuphatikizidwa ndi Co/MA chothandizira cha MDR, ndipo ndondomekoyi ikuwonetsedwa mkuyu. 3. osowa dziko olimbikitsa akhoza kusintha kubalalitsidwa wa Co pa MA chonyamulira ndi ziletsa agglomeration wa co particles. ang'onoang'ono tinthu kukula, mphamvu Co-MA mogwirizana, mphamvu chothandizira ndi sintering luso YCo/MA chothandizira, ndi zotsatira zabwino angapo olimbikitsa pa MDR ntchito ndi mpweya deposition.Fig. 4 ndi HRTEM iMage pambuyo pa chithandizo cha MDR ku 1023K, Co2: ch4: N2 = 1 ∶ 1 ∶ 3.1 kwa maola 8. Co particles alipo mu mawonekedwe a mawanga akuda, pamene MA zonyamulira alipo mu mawonekedwe a imvi, zomwe zimadalira kusiyana ma elekitironi kachulukidwe. mu HRTEM fano ndi 10% Co/MA (mkuyu. 4b), ndi agglomeration wa Co zitsulo particles zimawonedwa pa ma onyamulaKuwonjezera osowa dziko kulimbikitsa amachepetsa Co particles kuti 11.0nm ~ 12.5nm. YCo/MA ili ndi kulumikizana kolimba kwa Co-MA, ndipo magwiridwe ake a sintering ndiabwino kuposa zothandizira zina. kuwonjezera, monga momwe nkhuyu. 4b mpaka 4f, ma hollow carbon nanowires (CNF) amapangidwa pazitsulo, zomwe zimayenderana ndi kutuluka kwa gasi ndikuletsa chothandizira kuti chizimitsa.
Chithunzi cha 3 Zotsatira za kuchuluka kwapadziko lapansi kosowa kwambiri pazakuthupi ndi zamankhwala komanso magwiridwe antchito a MDR a Co/MA catalyst
3.2.2 Chothandizira cha deoxidation
Fe2O3/Meso-CeAl, chothandizira cha Ce-doped Fe-based deoxidation, chinakonzedwa ndi oxidative dehydrogenation ya 1-butene ndi CO2as soft oxidant, ndipo inagwiritsidwa ntchito popanga 1,3-butadiene (BD). Ce inali yomwazika kwambiri mu alumina matrix, ndipo Fe2O3/meso idabalalika kwambiriFe2O3/Meso-CeAl-100 chothandizira sikuti ili ndi mitundu yachitsulo yomwazika kwambiri komanso mawonekedwe abwino, komanso imakhala ndi mphamvu yabwino yosungiramo okosijeni, chifukwa chake imakhala ndi ma adsorption abwino komanso kuyambitsa mphamvu. ku CO2. Monga tawonetsera pa Chithunzi 5, zithunzi za TEM zikuwonetsa kuti Fe2O3/Meso-CeAl-100 ndi yokhazikikaIziwonetsa kuti njira yofanana ndi nyongolotsi ya MesoCeAl-100 ndi yotayirira komanso yopindika, yomwe imapindulitsa kufalikira kwa zinthu zomwe zimagwira ntchito, pomwe Ce. imayikidwa bwino mu alumina matrix. Zopangira zitsulo zabwino kwambiri zomwe zimakwaniritsa mulingo wotsika kwambiri wamagalimoto amagalimoto zapanga pore, kukhazikika kwa hydrothermal komanso mphamvu yayikulu yosungira mpweya.
3.2.3 Chothandizira Magalimoto
Pd-Rh idathandizira ma quaternary aluminiyamu osowa padziko lapansi AlCeZrTiOx ndi AlLaZrTiOx kuti apeze zida zokutira zamagalimoto. Pd-Rh/ALC ya mesoporous aluminium-based rare earth complex Pd-Rh/ALC itha kugwiritsidwa ntchito bwino ngati chothandizira kuyeretsa magalimoto a CNG ndikukhazikika bwino, komanso kusinthika kwa CH4, chigawo chachikulu cha CNG galimoto yotulutsa mpweya, ndi yokwera mpaka 97.8%. Gwiritsani ntchito njira imodzi ya hydrotherMAl yokonzekera kuti dziko lapansi likhale losawerengeka kuti lidzipangitse kudzipangira nokha, Kulamulira masoporous precursors okhala ndi metastable state and high aggregation anapangidwa, ndipo kaphatikizidwe ka RE-Al kumagwirizana ndi chitsanzo cha "compound growth unit" , motero kuzindikira kuyeretsedwa kwa utsi wagalimoto pambuyo wokwera njira zitatu chothandizira chosinthira.
Chithunzi cha 4 HRTEM zithunzi za ma (a), Co/ MA(b), LaCo/MA(c), CeCo/MA(d), YCo/MA(e) ndi SmCo/MA(f)
Chithunzi cha 5 TEM chithunzi (A) ndi chithunzi cha EDS (b,c) cha Fe2O3/Meso-CeAl-100
3.3 ntchito yowala
Ma electron a zinthu zapadziko lapansi osowa amasangalala mosavuta kusintha pakati pa milingo yosiyanasiyana ya mphamvu ndi kutulutsa kuwala. Ma ions osowa padziko lapansi nthawi zambiri amagwiritsidwa ntchito ngati zoyambitsa kupanga zida zowunikira. Ma ion a dziko lapansi osowa amatha kuikidwa pamwamba pa ma aluminium phosphate hollow microspheres pogwiritsa ntchito njira ya coprecipitation ndi njira yosinthira ma ion, ndipo zida zowunikira AlPO4∶RE(La,Ce,Pr,Nd) zitha kukonzedwa. Luminescent wavelength ili pafupi ndi dera la ultraviolet.MA imapangidwa kukhala mafilimu ochepa kwambiri chifukwa cha inertia, otsika dielectric mosasinthasintha komanso otsika conductivity, zomwe zimapangitsa kuti zigwiritsidwe ntchito ku zipangizo zamagetsi ndi kuwala, mafilimu owonda, zotchinga, masensa, ndi zina zotero. kugwiritsidwa ntchito pozindikira kuyankha kwa magalasi amtundu umodzi wazithunzi, kupanga mphamvu ndi zokutira zotsutsana ndi reflection. Zipangizozi zimakhala ndi mafilimu odzaza ndi kutalika kwa njira yotsimikizika, kotero ndikofunikira kuwongolera index ya refractive ndi makulidwe.Pakali pano, titanium dioxide ndi zirconium oxide yokhala ndi index yayikulu ya refractive ndi silicon dioxide yokhala ndi index yotsika ya refractive nthawi zambiri imagwiritsidwa ntchito popanga ndi kupanga zida zotere. . Kupezeka kwazinthu zokhala ndi mitundu yosiyanasiyana yamankhwala apamwamba kumakulitsidwa, zomwe zimapangitsa kuti zitheke kupanga masensa apamwamba a photon. Kuyambitsidwa kwa mafilimu a MA ndi oxyhydroxide popanga zida za kuwala kumasonyeza kuthekera kwakukulu chifukwa refractive index ndi yofanana ndi ya silicon dioxide.Koma katundu wa mankhwala ndi wosiyana.
3.4 kukhazikika kwamafuta
Ndi kuwonjezeka kwa kutentha, sintering imakhudza kwambiri kugwiritsa ntchito mphamvu ya MA chothandizira, ndipo malo enieni amachepa ndipo γ-Al2O3in crystalline gawo amasintha kukhala δ ndi θ mpaka χ magawo. Zida zapadziko lapansi zosawerengeka zimakhala ndi kukhazikika kwamankhwala komanso kukhazikika kwamafuta, kusinthasintha kwakukulu, komanso kupezeka mosavuta komanso zotsika mtengo. Kuwonjezera kwa zinthu zapadziko lapansi zosowa kungapangitse kukhazikika kwa kutentha, kukana kwa kutentha kwa okosijeni ndi makina onyamula katundu, ndikusintha acidity ya pamwamba pa carrier.La ndi Ce ndizo zomwe zimagwiritsidwa ntchito kwambiri ndikuphunziridwa kusinthidwa. Lu Weiguang ndi ena anapeza kuti Kuwonjezera osowa dziko zinthu mogwira analetsa chochuluka mayamwidwe a aluminiyamu particles, La ndi Ce anateteza magulu hydroxyl pamwamba pa aluminiyamu, inhibited sintering ndi gawo kusintha, ndi kuchepetsa kuwonongeka kwa kutentha kwapamwamba kwa dongosolo mesoporous. . The aluminiyamu wokonzeka akadali ndi mkulu enieni pamwamba ndi pore volume. Li Yanqiu et al. anawonjezera 5% La2O3to γ-Al2O3, zomwe zimathandizira kukhazikika kwamafuta ndikuwonjezera voliyumu ya pore ndi malo enieni a chonyamulira alumina. Monga tikuwonera pa Chithunzi 6, La2O3awonjezedwa ku γ-Al2O3, Sinthani kukhazikika kwa kutentha kwa chonyamulira chosowa padziko lapansi.
Mu ndondomeko ya doping nano-fibrous particles ndi La kuti MA, BET pamwamba m'dera ndi pore buku la MA-La ndi apamwamba kuposa MA pamene kutentha kutentha kutentha kutentha, ndi doping ndi La ndi zoonekeratu retarding zotsatira pa sintering pa mkulu. kutentha. monga zikuwonetsedwa mkuyu. 7, ndi kuwonjezeka kutentha, La linalake ndipo tikulephera mmene kukula kwambewu ndi gawo kusintha, pamene nkhuyu. 7a ndi 7c amasonyeza kudzikundikira kwa nano-fibrous particles. mu fig. 7b, awiri a particles lalikulu opangidwa ndi calcination pa 1200 ℃ pafupifupi 100nm. Kuphatikiza apo, poyerekeza ndi MA-1200, MA-La-1200 sichimaphatikizana pambuyo pa chithandizo cha kutentha. Kuphatikiza kwa La, tinthu tating'onoting'ono ta nano-fiber timakhala ndi luso lapamwamba la sintering. ngakhale kutentha kwakukulu kwa calcination, doped La imabalalikabe pamtunda wa MA. La kusinthidwa MA angagwiritsidwe ntchito ngati chonyamulira cha Pd chothandizira mu C3H8oxidation reaction.
Chithunzi cha 6 Chojambula chamtundu wa aluminiyamu wonyezimira wokhala ndi komanso wopanda zinthu zapadziko lapansi
Chithunzi cha 7 TEM zithunzi za MA-400 (a), MA-1200(b), MA-La-400(c) ndi MA-La-1200(d)
4 Mapeto
Kupita patsogolo kwa kukonzekera ndi kugwiritsa ntchito zida za MA zosinthidwa zasomwe padziko lapansi kumayambitsidwa. Rare earth modified MA imagwiritsidwa ntchito kwambiri. Ngakhale kuti kafukufuku wambiri wachitika pothandizira, kukhazikika kwamafuta ndi kutsatsa, zida zambiri zimakhala ndi mtengo wokwera, kuchuluka kwa doping, kusakhazikika bwino komanso zovuta kupanga mafakitale. Ntchito yotsatirayi iyenera kuchitika mtsogolomu: konzani kapangidwe kake ndi kapangidwe ka MA osowa padziko lapansi, sankhani njira yoyenera, Kumanani ndi chitukuko cha ntchito; Khazikitsani njira yoyendetsera ntchito potengera njira zogwirira ntchito kuti muchepetse ndalama ndikuzindikira kupanga mafakitale; Kuti tichulukitse ubwino wa chuma chosowa cha dziko la China, tiyenera kufufuza njira ya osowa Earth MA kusinthidwa, kusintha chiphunzitso ndi ndondomeko kukonzekera osowa Earth kusinthidwa MA.
Fund Project: Shaanxi Science and Technology Overall Innovation Project (2011KTDZ01-04-01); Chigawo cha Shaanxi 2019 Special Scientific Research Project (19JK0490); Ntchito yapadera yofufuza zasayansi ya 2020 ya Huaqing College, Xi 'an University of Architecture and Technology (20KY02)
Chitsime: Rare Earth
Nthawi yotumiza: Jun-15-2021