Single-phase proton- and electron-conducting Ag-organic coordination polymers for efficient CO2 electroreduction

Abstract

Here a single-phase proton- and electron-conducting metal–organic coordination polymer (MOCP) electrocatalyst for the CO₂ reduction reaction (CO₂RR) was constructed by using Ag as the metal center and 1H-1,2,3-triazole (Tz) as the ligand. To evaluate the effects of tuning the conductivity of Ag-MOCP on CO₂RR performances, another Ag-MOCP was selected for comparison by using 1H-benzotriazole (Btz) as the ligand. The proton conductivity for Ag-MOCP-Tz is 2.3 × 10⁻⁷ S cm⁻¹, 70-fold that for Ag-MOCP-Btz with 3.3 × 10⁻⁹ S cm⁻¹ at 25 °C and 98% RH. And the electron conductivity of Ag-MOCP-Tz (3.57 × 10⁻⁷ S cm⁻¹) is 120 times that of Ag-MOCP-Btz (2.96 × 10⁻⁹ S cm⁻¹) at 25 °C. Meanwhile the FE_CO of Ag-MOCP-Tz is 85.9% at −0.98 V vs. RHE, which is better than that of Ag-MOCP-Btz with 65.4%.