Ag-doped Co3O4 catalyst derived from heterometallic MOF for syngas production by electrocatalytic reduction of CO2 in water

Electrocatalytic reduction of CO 2 to useful fuels or chemicals is a promising path for carbon recycling. In this study, a novel mixed-metallic MOF [Ag 4 Co 2 (pyz)PDC 4 ][Ag 2 Co(pyz) 2 PDC 2 ] was synthesized, and it transformed into Ag doped Co 3 O 4 catalyst, which exhibits excellent electro-catalytic performance for reduction of CO 2 in water to syngas (H 2 + CO). The as-prepared Ag/Co 3 O 4 material exhibits a high selectivity of CO in 0.1 M KHCO 3 aqueous solution (CO 2 saturated) with the corresponding faradaic efficiency up to 55.6%. Compared with the Ag/Co 3 O 4 electrode, the maximum faradaic efficiency (FE) of CO of pure Co 3 O 4 is 21.3% at − 1.8 V vs. SCE. The results show that the presence of Ag can improve the efficiency of CO significantly, thereby inhibiting the production of H 2 . The stability of the samples can be maintained for more than 10 h at − 1.8 V vs. SCE. The ratio of production between H 2 and CO can be controlled by varying the potential values.