Regulation of surface oxygen vacancy of Cu-CeO2/TiO2 heterostructures via fast Joule heating method for enhanced CO2 electrochemical reduction

Abstract

Strict control of carbon emissions is crucial for expediting the achievement of carbon neutrality. However, the current CO₂RR electrocatalytic exhibits numerous shortcomings that impede the enhancement of catalytic activity. Issues such as lengthy catalyst preparation times, and high levels of precious metal content. Additionally, the aggregation of ultrafine nanoparticles contributes to a rapid deterioration in catalytic performance. Herein, a Joule-heating method is efficiently utilized to synthesize heterostructures nano-catalysts for CO₂ electroreduction on carbon cloth substrates. This method takes advantage of the thermoelectric coupling of the carbon cloth to achieve carbothermal reduction, while also regulating phase composition and introduction of oxygen vacancies. The Cu-CeO₂/TiO₂/CC catalyst synthesized in this method showed a current density in CO₂ of −32 mA·cm⁻² at −1.0 V (vs. RHE). Notably, this catalyst demonstrated high CO selectivity and Faraday efficiency (FE_CO) of up to 82.5 % at a low potential of −0.3 V (vs. RHE). Optimal electrochemical performance is achieved at a power of 40 W. The ultra-fast temperature change process prevented the agglomeration of catalyst particles and facilitated the construction of a stable heterogeneous interface with a high oxygen vacancy concentration. In conclusion, this study presents a promising approach, particularly for the rapid preparation of low-cost, highly selective non-precious metal electrocatalysts.