Enhancing Electroreduction of CO2 to Formate of Pd Catalysts Loaded on TiO2 Nanotubes Arrays by N, B‐Support Modification

Electrochemical reduction of CO2 to formate in aqueous electrolyte is a potentially effective route for energy storage and resource utilization of CO2. Pd is known as excellent catalyst for CO2 electrochemical reduction, however, the selectivity to formate on Pd catalysts was limited to narrow potential window which may restrict their applications. Herein, N, B‐doped TiO2 nanotube arrays (TNTA) were designed and synthesized to reveal the metal‐support interaction and its effects on the electrochemical reduction of CO2. The N, B doped TNTA supported Pd catalysts were found to highly enhance the activity with 3.7 and 4.6 times and the selectivity with 2 and 2.6 times comparing respectively to undoped one for CO2 electrochemical reduction to formate at −1.0 V vs SCE. The enhancement of formate production can be attributed to the modification of electron structure facilitating the stabilization of active Pd hydride phase and suppressing the CO formation. This study will shed light on strategies to improve the performance of catalysts via the functionalization of supports in field of CO2 selective electrochemical reduction. Electrocatalytic reduction of CO2 to formate was enhanced by doping TiO2 nanotubes arrays support with N and B. The significant enhancement can be attributed to the Pd electronic structure modification that facilitates the stabilization of active Pd hydride phase and suppresses the CO formation.