Gcwalisa ifomu elingezansi futhi sizokuthumela i-imeyili ngenguqulo ye-PDF ethi “Ukuthuthukiswa kobuchwepheshe obusha bokuguqula i-carbon dioxide ibe uphethiloli owuketshezi”
I-Carbon dioxide (CO2) ingumkhiqizo wokushisa amafutha ezinto ezilahliwe kanye negesi evame kakhulu yokushisa, engaguqulwa ibe amafutha awusizo ngendlela eqhubekayo. Enye indlela ethembisayo yokuguqula ukukhishwa kwe-CO2 kube ukudla okuphakelayo kwamafutha inqubo ebizwa ngokuthi ukunciphisa kwe-electrochemical. Kodwa ukuze isebenze kahle kwezentengiselwano, inqubo idinga ukuthuthukiswa ukuze kukhethwe noma kukhiqizwe imikhiqizo ecebile kakhulu yekhabhoni efiselekayo. Manje, njengoba kubikiwe ephephabhukwini i-Nature Energy, i-Lawrence Berkeley National Laboratory (i-Berkeley Lab) isungule indlela entsha yokuthuthukisa ubuso be-catalyst yethusi esetshenziselwa ukusabela okusizayo, ngaleyo ndlela kwandiswe ukukhetha kwenqubo.
“Nakuba sazi ukuthi ithusi liyisisusa esihle kakhulu salokhu kusabela, alinikezi ukukhetha okuphezulu komkhiqizo owufunayo,” kusho u-Alexis, usosayensi omkhulu eMnyangweni Wezesayensi Yezamakhemikhali eBerkeley Lab kanye noprofesa wobunjiniyela bamakhemikhali eNyuvesi yaseCalifornia, eBerkeley. USpell uthe. “Ithimba lethu lithole ukuthi ungasebenzisa indawo yasendaweni yesisusa ukwenza amaqhinga ahlukahlukene ukuze unikeze lolu hlobo lokukhetha.”
Ezifundweni zangaphambilini, abacwaningi basungule izimo eziqondile ukuze banikeze indawo engcono kakhulu kagesi namakhemikhali yokudala imikhiqizo ecebile ngekhabhoni enenani lezentengiselwano. Kodwa lezi zimo ziphambene nezimo ezenzeka ngokwemvelo kumaseli kaphethiloli ajwayelekile asebenzisa izinto ezisebenzisa amanzi.
Ukuze kutholakale umklamo ongasetshenziswa endaweni yamanzi e-fuel cell, njengengxenye yephrojekthi ye-Energy Innovation Center ye-Liquid Sunshine Alliance yoMnyango Wezamandla, uBell nethimba lakhe baphendukela kungqimba oluncane lwe-ionomer, oluvumela ama-molecule athile ashajiwe (ama-ion) ukuthi adlule. Susa amanye ama-ion. Ngenxa yezakhiwo zawo zamakhemikhali ezikhethiwe kakhulu, afaneleka kakhulu ukuba nomthelela onamandla endaweni encane.
UChanyeon Kim, umcwaningi we-postdoctoral eqenjini le-Bell kanye nombhali wokuqala wephepha, uphakamise ukumboza ubuso be-catalysts zethusi ngama-ionomer amabili avamile, i-Nafion kanye ne-Sustaination. Ithimba licabange ukuthi ukwenza kanjalo kufanele kushintshe indawo eseduze ne-catalyst—kufaka phakathi i-pH kanye nenani lamanzi kanye ne-carbon dioxide—ngendlela ethile ukuqondisa ukusabela ekukhiqizeni imikhiqizo ecebile nge-carbon engaguqulwa kalula ibe amakhemikhali awusizo. Imikhiqizo kanye namafutha oketshezi.
Abacwaningi basebenzise ungqimba oluncane lwe-ionomer ngayinye kanye nongqimba oluphindwe kabili lwe-ionomer ezimbili kufilimu yethusi esekelwa yizinto ze-polymer ukuze bakhe ifilimu, abangayifaka eduze kokuphela kweseli le-electrochemical eliyisimo sesandla. Lapho befaka i-carbon dioxide ebhethrini futhi besebenzisa i-voltage, balinganisa ugesi ophelele ogeleza ebhethrini. Base belinganisa igesi noketshezi oluqoqwe echibini eliseduze ngesikhathi sokusabela. Ecaleni elinezingqimba ezimbili, bathole ukuthi imikhiqizo ecebile nge-carbon yayibalelwa ku-80% wamandla asetshenziswa ukusabela—okungaphezu kuka-60% ecaleni elingamboziwe.
“Lokhu kuhlanganiswa kwesangweji kunikeza okungcono kakhulu kuzo zombili lezi zindawo: ukukhetha okuphezulu komkhiqizo kanye nomsebenzi ophezulu,” kusho uBell. Ubuso obunezingqimba ezimbili abugcini nje ngokuba muhle emikhiqizweni ecebile ngekhabhoni, kodwa futhi bukhiqiza ugesi onamandla ngesikhathi esifanayo, okubonisa ukwanda komsebenzi.
Abacwaningi baphetha ngokuthi impendulo ethuthukisiwe iwumphumela wokuhlushwa okuphezulu kwe-CO2 okuqongelelwe embozweni ngqo phezu kwethusi. Ngaphezu kwalokho, ama-molecule ashaje kabi aqongelela esifundeni esiphakathi kwama-ionomer amabili azokhiqiza i-asidi ephansi yendawo. Lokhu kuhlanganiswa kuqeda ukuhwebelana kokuhlushwa okuvame ukwenzeka lapho kungekho amafilimu e-ionomer.
Ukuze bathuthukise ukusebenza kahle kokusabela, abacwaningi baphendukele kubuchwepheshe obufakazelwe ngaphambilini obungadingi ifilimu ye-ionomer njengenye indlela yokwandisa i-CO2 kanye ne-pH: i-voltage evuvukile. Ngokusebenzisa i-voltage evuvukile embozweni we-ionomer ongqimba oluphindwe kabili, abacwaningi bathole ukwanda okungu-250% emikhiqizweni ecebile ngekhabhoni uma kuqhathaniswa nethusi elingavuvukile kanye ne-voltage engaguquki.
Nakuba abanye abacwaningi begxila emsebenzini wabo ekuthuthukisweni kwama-catalyst amasha, ukutholakala kwe-catalyst akunaki izimo zokusebenza. Ukulawula indawo ezungezile ebusweni be-catalyst kuyindlela entsha nehlukile.
“Asizange siqhamuke ne-catalyst entsha ngokuphelele, kodwa sisebenzise ukuqonda kwethu i-reaction kinetics futhi sasebenzisa lolu lwazi ukusiqondisa ekucabangeni ngendlela yokushintsha indawo ye-catalyst,” kusho u-Adam Weber, unjiniyela omkhulu. Ososayensi emkhakheni wezobuchwepheshe bamandla eBerkeley Laboratories kanye nombhali-mbhali wamaphepha.
Isinyathelo esilandelayo ukwandisa ukukhiqizwa kwama-catalyst amboziwe. Ukuhlolwa kokuqala kwethimba le-Berkeley Lab kuhilele izinhlelo ezincane zamamodeli ayisicaba, ezazilula kakhulu kunezakhiwo ezinkulu ezinezimbobo ezidingekayo ekusetshenzisweni kwezentengiselwano. “Akunzima ukufaka upende endaweni eyisicaba. Kodwa izindlela zezentengiselwano zingase zihilele ukumboza amabhola amancane ethusi,” kusho uBell. Ukwengeza ungqimba lwesibili lopende kuba yinselele. Enye indlela ukuxuba nokufaka upende ndawonye ku-solvent, bese uthemba ukuthi uzohlukana lapho upende uphela. Kuthiwani uma kungenjalo? UBell uphethe ngokuthi: “Sidinga nje ukuba nobuhlakani.” Bheka uKim C, uBui JC, uLuo X nabanye. I-catalyst microenvironment eyenziwe ngokwezifiso yokunciphisa i-CO2 nge-electro-reduction kumikhiqizo ye-multi-carbon kusetshenziswa upende we-ionomer onezingqimba ezimbili ku-copper. I-Nat Energy. 2021;6(11):1026-1034. doi:10.1038/s41560-021-00920-8
Lesi sihloko sithathwe ezintweni ezilandelayo. Qaphela: Izinto kungenzeka ukuthi zihlelwe ngobude nokuqukethwe. Ukuze uthole ulwazi olwengeziwe, sicela uxhumane nomthombo ocashuniwe.
Isikhathi sokuthunyelwe: Novemba-22-2021
