Pd20Te7 Nanowires as an Efficient Multifunctional Catalyst for CO2 and O2 Electroreduction.

Abstract

Discovering a multifunctional electrocatalyst that can achieve the selective electrochemical reduction of a variety of small molecules (such as CO₂ and O₂, etc.) is a highly promising process. However, most reported Pd-based nanomaterials can only convert one kind of small molecule. In this study, we have constructed Pd₂₀Te₇ intermetallic nanowires (Pd₂₀Te₇ NWs) with numerous low-coordinated atoms, which can serve as an efficient and multifunctional catalyst for CO₂ reduction reaction (CO₂RR) and oxygen reduction reaction (ORR). For CO₂RR, Pd₂₀Te₇ NWs can achieve CO Faraday efficiency (FE_CO) of 96.2% at the potential of -0.8 V versus RHE. For ORR, Pd₂₀Te₇ NWs have selectivity for H₂O₂ of over 90%. Moreover, at 0.2 V versus RHE, the H₂O₂ production rate of Pd₂₀Te₇ NWs can achieve 1624.2 mmol g_Pd ^-1 h^-1, which is approximately 8.5 times that of Pd NWs. Compared with Pd NWs, the optimized electronic structure and surface morphology of Pd₂₀Te₇ NWs balance the adsorption of COOH* and CO* on the catalyst during CO₂RR and change the adsorption mode of O₂ (side-on to end-on) during ORR, thus promoting CO and H₂O₂ generation during CO₂RR and ORR, respectively. This work highlights the importance of electronic structure and surface morphology modification of metal catalysts for electrocatalytic reactions.