Yifei Li, Karin U. D. Calvinho, Mahak Dhiman, Anders B. Laursen, Hengfei Gu, Dominick Santorelli, Zachary Clifford and G. Charles Dismukes
{"title":"按需调节产品选择性:用于二氧化碳电还原乙二醇的机制引导型路易斯酸助催化剂","authors":"Yifei Li, Karin U. D. Calvinho, Mahak Dhiman, Anders B. Laursen, Hengfei Gu, Dominick Santorelli, Zachary Clifford and G. Charles Dismukes","doi":"10.1039/D3EY00237C","DOIUrl":null,"url":null,"abstract":"<p >Bioinspired nickel phosphide electrocatalysts can produce more complex multi-carbon products than natural photosynthetic enzymes but controlling C-product selectivity and suppressing H<small><sub>2</sub></small> evolution remain open challenges. Here, we report a significant shift in the CO<small><sub>2</sub></small>RR product distribution on Ni<small><sub>2</sub></small>P in the presence of boric acid/borate, a soluble Lewis acid/base co-catalyst. Using Ni<small><sub>2</sub></small>P without a co-catalyst, CO<small><sub>2</sub></small> reduction produces a mixture of methyl glyoxal (C<small><sub>3</sub></small>) > 2,3-furnadiol (C<small><sub>4</sub></small>) and formic acid (C<small><sub>1</sub></small>) with 100% Faradaic efficiency for carbon products. Addition of boric acid/borate shifts product selectivity to ethylene glycol (EG) with an 85% CO<small><sub>2</sub></small>-Faradaic efficiency (at 10 mM, 0 V <em>vs.</em> RHE), with the balance being the aforementioned C<small><sub>1</sub></small>, C<small><sub>3</sub></small> and C<small><sub>4</sub></small> products. The mechanism of EG formation is proposed to occur by the co-catalyst activating a reaction between surface *hydride and *glycolaldehyde on Ni<small><sub>2</sub></small>P, while suppressing the aldol C–C coupling reaction that forms the C<small><sub>3</sub></small> and C<small><sub>4</sub></small> products. The formation of an intermediate borate-EG-diester, [(OCH<small><sub>2</sub></small>CHO)<small><sub>2</sub></small>B]<small><sup>−</sup></small>, is detected by <small><sup>11</sup></small>B-NMR, which hydrolyzes to release the EG product. Extended electrolysis of boric acid modifies the surface of Ni<small><sub>2</sub></small>P by forming *BO<small><sub>3</sub></small>–Ni<small><sub>2</sub></small>P, as shown by XPS. CO<small><sub>2</sub></small> electro-reduction on *BO<small><sub>3</sub></small>–Ni<small><sub>2</sub></small>P in the absence of free boric acid produces exclusively ethylene oxide (EO), which slowly hydrolyzes to EG in the bicarbonate electrolyte. The combined Faradaic efficiencies for CO<small><sub>2</sub></small>RR products EO + EG with free boric acid as the co-catalyst and *BO<small><sub>3</sub></small>–Ni<small><sub>2</sub></small>P as the cathode reaches 88% (at 0 V <em>vs</em>. RHE), a record carbon selectivity. This work illustrates the feasibility of using Lewis acid/base co-catalysts to change the established chemical reaction mechanism of an electrocatalyst to form a new, chemically predictable, more valuable product in high yield.</p>","PeriodicalId":72877,"journal":{"name":"EES catalysis","volume":" 3","pages":" 823-833"},"PeriodicalIF":0.0000,"publicationDate":"2024-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2024/ey/d3ey00237c?page=search","citationCount":"0","resultStr":"{\"title\":\"Tunable product selectivity on demand: a mechanism-guided Lewis acid co-catalyst for CO2 electroreduction to ethylene glycol†\",\"authors\":\"Yifei Li, Karin U. D. Calvinho, Mahak Dhiman, Anders B. Laursen, Hengfei Gu, Dominick Santorelli, Zachary Clifford and G. Charles Dismukes\",\"doi\":\"10.1039/D3EY00237C\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p >Bioinspired nickel phosphide electrocatalysts can produce more complex multi-carbon products than natural photosynthetic enzymes but controlling C-product selectivity and suppressing H<small><sub>2</sub></small> evolution remain open challenges. Here, we report a significant shift in the CO<small><sub>2</sub></small>RR product distribution on Ni<small><sub>2</sub></small>P in the presence of boric acid/borate, a soluble Lewis acid/base co-catalyst. Using Ni<small><sub>2</sub></small>P without a co-catalyst, CO<small><sub>2</sub></small> reduction produces a mixture of methyl glyoxal (C<small><sub>3</sub></small>) > 2,3-furnadiol (C<small><sub>4</sub></small>) and formic acid (C<small><sub>1</sub></small>) with 100% Faradaic efficiency for carbon products. Addition of boric acid/borate shifts product selectivity to ethylene glycol (EG) with an 85% CO<small><sub>2</sub></small>-Faradaic efficiency (at 10 mM, 0 V <em>vs.</em> RHE), with the balance being the aforementioned C<small><sub>1</sub></small>, C<small><sub>3</sub></small> and C<small><sub>4</sub></small> products. The mechanism of EG formation is proposed to occur by the co-catalyst activating a reaction between surface *hydride and *glycolaldehyde on Ni<small><sub>2</sub></small>P, while suppressing the aldol C–C coupling reaction that forms the C<small><sub>3</sub></small> and C<small><sub>4</sub></small> products. The formation of an intermediate borate-EG-diester, [(OCH<small><sub>2</sub></small>CHO)<small><sub>2</sub></small>B]<small><sup>−</sup></small>, is detected by <small><sup>11</sup></small>B-NMR, which hydrolyzes to release the EG product. Extended electrolysis of boric acid modifies the surface of Ni<small><sub>2</sub></small>P by forming *BO<small><sub>3</sub></small>–Ni<small><sub>2</sub></small>P, as shown by XPS. CO<small><sub>2</sub></small> electro-reduction on *BO<small><sub>3</sub></small>–Ni<small><sub>2</sub></small>P in the absence of free boric acid produces exclusively ethylene oxide (EO), which slowly hydrolyzes to EG in the bicarbonate electrolyte. The combined Faradaic efficiencies for CO<small><sub>2</sub></small>RR products EO + EG with free boric acid as the co-catalyst and *BO<small><sub>3</sub></small>–Ni<small><sub>2</sub></small>P as the cathode reaches 88% (at 0 V <em>vs</em>. RHE), a record carbon selectivity. This work illustrates the feasibility of using Lewis acid/base co-catalysts to change the established chemical reaction mechanism of an electrocatalyst to form a new, chemically predictable, more valuable product in high yield.</p>\",\"PeriodicalId\":72877,\"journal\":{\"name\":\"EES catalysis\",\"volume\":\" 3\",\"pages\":\" 823-833\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2024-01-26\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://pubs.rsc.org/en/content/articlepdf/2024/ey/d3ey00237c?page=search\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"EES catalysis\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://pubs.rsc.org/en/content/articlelanding/2024/ey/d3ey00237c\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"EES catalysis","FirstCategoryId":"1085","ListUrlMain":"https://pubs.rsc.org/en/content/articlelanding/2024/ey/d3ey00237c","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
Tunable product selectivity on demand: a mechanism-guided Lewis acid co-catalyst for CO2 electroreduction to ethylene glycol†
Bioinspired nickel phosphide electrocatalysts can produce more complex multi-carbon products than natural photosynthetic enzymes but controlling C-product selectivity and suppressing H2 evolution remain open challenges. Here, we report a significant shift in the CO2RR product distribution on Ni2P in the presence of boric acid/borate, a soluble Lewis acid/base co-catalyst. Using Ni2P without a co-catalyst, CO2 reduction produces a mixture of methyl glyoxal (C3) > 2,3-furnadiol (C4) and formic acid (C1) with 100% Faradaic efficiency for carbon products. Addition of boric acid/borate shifts product selectivity to ethylene glycol (EG) with an 85% CO2-Faradaic efficiency (at 10 mM, 0 V vs. RHE), with the balance being the aforementioned C1, C3 and C4 products. The mechanism of EG formation is proposed to occur by the co-catalyst activating a reaction between surface *hydride and *glycolaldehyde on Ni2P, while suppressing the aldol C–C coupling reaction that forms the C3 and C4 products. The formation of an intermediate borate-EG-diester, [(OCH2CHO)2B]−, is detected by 11B-NMR, which hydrolyzes to release the EG product. Extended electrolysis of boric acid modifies the surface of Ni2P by forming *BO3–Ni2P, as shown by XPS. CO2 electro-reduction on *BO3–Ni2P in the absence of free boric acid produces exclusively ethylene oxide (EO), which slowly hydrolyzes to EG in the bicarbonate electrolyte. The combined Faradaic efficiencies for CO2RR products EO + EG with free boric acid as the co-catalyst and *BO3–Ni2P as the cathode reaches 88% (at 0 V vs. RHE), a record carbon selectivity. This work illustrates the feasibility of using Lewis acid/base co-catalysts to change the established chemical reaction mechanism of an electrocatalyst to form a new, chemically predictable, more valuable product in high yield.