We demonstrated an efficient solar photovoltaic-powered electrochemical CO2 reduction device with a high-pressure CO2-captured liquid feed.In an"air-to-barrel"picture,this device holds promise to avoid both high-temperature gaseous CO2 regeneration and high energy-cost gas product separation steps,while these steps are necessary for devices with a gaseous CO2 feed.To date,solar fuel production with a CO2-saturated liquid feed suffers from high over-potential to suppress the hydrogen evolution reaction and consequently,low solar-to-chemical(STC)energy conversion efficiency.Here,we presented a dis-tinct high-pressure operando strategy,i.e.,we took extra advantage of the high pressure in catalyst syn-thesis besides in the period of the CO2 reduction reaction(CO2RR).The power of this strategy was demonstrated by a proof-of-concept device in which a representative copper catalyst was first synthe-sized in operando in a high-pressure(50 bar)CO2-saturated KHCO3 solution,and then this high-pressure CO2-captured liquid was converted to solar fuel using the operando synthesized Cu catalyst.This Cu catalyst achieved 95％CO2RR selectivity at the recorded low potential of-0.3 V vs.RHE enabled by the combination of operando facet engineering and oxide derivation.Furthermore,this device achieved a record-high STC efficiency of 21.6％under outdoor illumination,superior to other CO2-saturated liquid-fed devices,and compared favorably to gaseous CO2-fed devices.

Kai Deng;Ying Zhang;Hao Feng;Ning Liu;Lushan Ma;Jingjing Duan;Yongjie Wang;Dong Liu;Qiang Li

MIIT Key Laboratory of Thermal Control of Electronic Equipment,School of Energy and Power Engineering,Nanjing University of Science and Technology,Nanjing 210094,China;School of Science,Harbin Institute of Technology,Shenzhen 518055,China

科学通报（英文版）

[1]Kai Deng;Ying Zhang;Hao Feng;Ning Liu;Lushan Ma;Jingjing Duan;Yongjie Wang;Dong Liu;Qiang Li-.Efficient solar fuel production with a high-pressure CO2-captured liquid feed)[J].科学通报（英文版）,2022(14):1467-1476

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