Sekuyisikhathi eside ososayensi bazi ukuthi iplatinamu iyisisusa esingcono kakhulu sokuhlukanisa ama-molecule amanzi ukuze akhiqize igesi ye-hydrogen. Ucwaningo olusha olwenziwa abacwaningi baseBrown University lubonisa ukuthi kungani iplatinum isebenza kahle kangaka—futhi akusona isizathu esicatshangwayo.

Ucwaningo, olushicilelwe ku-ACS Catalysis, lusiza ukuxazulula umbuzo wocwaningo wekhulunyaka, kusho ababhali. Futhi ingasiza ekuklameni izinto ezintsha zokukhiqiza i-hydrogen ezishibhile futhi eziyinala kuneplatinamu. Lokho kungasiza ekugcineni ekwehliseni ukungcola okuvela kumafutha ezinsalela ezimbiwa phansi.

"Uma singathola ukuthi singayenza kanjani i-hydrogen ngemali eshibhile nangempumelelo, kuvula umnyango wezixazululo eziningi ze-pragmatic zamafutha namakhemikhali angenazinsalela ezimbiwa phansi," kusho u-Andrew Peterson, uprofesa ohlangene eBrown's School of Engineering kanye nomlobi ophezulu wocwaningo. . “I-hydrogen ingasetshenziswa kuma-fuel cell, ehlanganiswe ne-CO2 eyeqile ukwenza uphethiloli noma ihlanganiswe ne-nitrogen ukwenza umanyolo we-ammonia. Kuningi esingakwenza nge-hydrogen, kodwa ukwenza amanzi ahlukanise abe umthombo we-hydrogen oyingozi, sidinga isisetshenziswa esishibhile.”

Ukuklama ama-catalyst amasha kuqala ngokuqonda ukuthi yini eyenza iplatinamu ikhetheke kangaka kulokhu kusabela, uPeterson uthi, futhi yilokho lolu cwaningo olusha oluhlose ukukuthola.

Impumelelo yePlatinamu kade kuthiwa ibangelwa amandla ayo okubopha “ama-Goldilocks”. Ama-catalyst afanelekile abambelele kuma-molecule asabelayo awakhululekile kakhulu noma aqine kakhulu, kodwa endaweni ethile phakathi. Hlanganisa ama-molecule ngokukhululeka futhi kunzima ukuqalisa ukusabela. Zibophe ziqine kakhulu futhi ama-molecule anamathele endaweni ye-catalyst, okwenza ukusabela kube nzima ukuqedela. Amandla abophezelayo e-hydrogen ku-platinum avele alinganisele kahle izingxenye ezimbili zokusabela kokuhlukana kwamanzi—ngakho ososayensi abaningi baye bakholelwa ukuthi yileso sici esenza iplatinamu ibe yinhle kakhulu.

Kodwa bekunezizathu zokungabaza ukuthi leso sithombe besilungile yini, kusho uPeterson. Isibonelo, into ebizwa nge-molybdenum disulfide (MoS2) inamandla okubopha afana neplatinamu, nokho iyisisusa esibi kakhulu sokusabela kokuhlukana kwamanzi. Lokho kusikisela ukuthi amandla okubopha angeke kube indaba ephelele, kusho uPeterson.

Ukuze bathole ukuthi kwakwenzekani, yena nozakwabo bahlola ukuhlukana kwamanzi emshinini we-platinum besebenzisa indlela ekhethekile abayenza ukuze balingise indlela ama-athomu nama-electron asebenza ngayo ekuphenduleni kwamakhemikhali kagesi.

Ukuhlaziywa kubonise ukuthi ama-athomu e-hydrogen aboshelwe ebusweni beplatinamu “kuma-Goldilocks” amandla abophayo awabambi iqhaza nhlobo ekuphenduleni lapho izinga lokusabela liphezulu. Kunalokho, zigxumeka phakathi kongqimba lwe-crystalline olungaphezulu lwe-platinum, lapho zihlala ziyizibukeli ezingenangqondo. Ama-athomu e-hydrogen abamba iqhaza ekuphenduleni abophekile ngokubuthakathaka kakhulu kunamandla okuthiwa "ama-Goldilocks". Futhi kunokuba zihlale ku-lattice, zihlala phezu kwama-athomu eplatinamu, lapho zikhululekile khona ukuhlangana ukuze zenze igesi ye-H2.

Yileyo nkululeko yokunyakaza kwama-athomu e-hydrogen phezulu okwenza iplatinamu isebenze kakhulu, kuphetha abacwaningi.

“Lokhu okusitshela khona ukuthi ukufuna la mandla okubopha i-'Goldilocks' akuwona umgomo olungile womklamo wendawo yokusebenza okuphezulu," kusho uPeterson. "Siphakamisa ukuthi ukuklama ama-catalyst abeka i-hydrogen kulesi simo esihamba kakhulu nesisebenzayo kuyindlela okufanele uhambe ngayo."