Active and selective CO2 electroreduction on a hierarchically nanoporous Au-Ag shell

Abstract We demonstrate an approach to fabricate hierarchically nanoporous Au-Ag shells (NPASs) with a hollow interior and nanoscale pores on the shell. Current density on the NPASs with pore size of 12 nm (NPAS12) is 2.9 and 1.8 times higher than that on Au nanoparticles (NPs) and Ag NPs, respectively. Meanwhile, the NPAS12 exhibits the highest CO Faradaic efficiency (FECO) of 86.4% at -0.85 V which is 11.6% and 31.2% higher than that of the Au NPs and Ag NPs, respectively. These results reveal that mass transport within the hierarchical pores plays a critical role in carbon dioxide electroreduction (CO2ER).