Coupling EC CO2 reduction on PhC2Cu-gas diffusion electrode with PEC glycerol oxidation on AuCu/TiO2HNTAs

Abstract

Coupling electrocatalytic (EC) CO₂ reduction with value-added oxidation reaction have attracted many attentions due to its significance in alleviating the environment and energy issues. Here, we constructed copper phenylacetylide (PhC₂Cu)-based gas diffusion electrode and applied it in EC CO₂RR for the first time. We also engineered AuCu-loading TiO₂ hieratical nanotube arrays (AuCu/TiO₂HNTAs) for photoelectocatalytic (PEC) glycerol oxidation. Results showed that 10% weight percent of PhC₂Cu could achieve 1:1 H₂/CO product as syngas at -0.7 V vs. RHE. The AuCu loading could dramatically enhance the catalyst performance. A photocurrent density of > 0.6 mA/cm² could be obtained with 0.05 wt% AuCu₄ in the presence of 0.01 M glycerol, much higher than pure TiO₂HNTAs and monometallic counterparts. Ethanol and CO₂ are the products in anodic chamber, the latter of which could be potentially used as reactant in the cathode chamber. The prepared cathode and anode work well in the overall reaction system.