Porous Palladium Nanomeshes with Enhanced Electrochemical CO₂‐into‐Syngas Conversion over a Wider Applied Potential

Abstract

Electrochemical conversion of CO2 into syngas, which can be used directly in the classical petroleum industrial processes, provides a powerful approach for achieving the recycling of anthropogenic carbon. Pd has previously been reported to be capable of converting CO2 into syngas with various CO/H2 ratios, but only at limited applied potential, which is mainly attributed to fewer active sites exposed toward electrocatalysis. Herein, high‐performance Pd nanomeshes (NMs) assembled with branch‐like Pd nanoparticles were designed and synthesized by using a simple interface‐induced self‐assembly strategy; these NMs could catalyze CO2‐into‐syngas conversion with a high current density in a wide applied potential range from −0.5 to −1.0 V (vs. reversible hydrogen electrode). Further evidence validated that the enhanced activity of the Pd NMs was not only caused by the crosslinked network structure accelerating electron transport, but also by the greater number of edge and/or corner active sites exposed on the surface of the NMs, which facilitated CO2 adsorption, CO2.− formation, COOH* stabilization, and CO generation. Under optimal operating conditions, Pd NMs could balance two competing reactions: CO2 reduction and hydrogen evolution. The resultant syngases with the ideal and tunable CO/H2 ratio between 0.5:1 and 1:1 could be used directly for methanol synthesis and Fischer–Tropsch reactions.

Recent Advances on Nanomaterials for Electrocatalytic CO2 Conversion

“…Cheng et al used quantum mechanics to study the space confinement effect on the performance of Ag and Au NPs for ECC to CO. 54 Pd nanomeshes assembled with branchlike Pd NPs for ECC to CO. 56 The electrochemical conversion from CO 2 to tunable syngas can be realized within a range of applied potential from −0.5 to −0.9 V vs RHE. This was attributed to open channels as well as exposed edge and/or corner active sites, which accelerate charge transmission and facilitate CO 2 adsorption, CO 2…”

“…Sargent et al found that NPs with high-index facets could suppress CO poisoning and simultaneously promote formic acid synthesis . Pd NPs with abundant high-index surfaces exhibit FE of 97%, and a current density of 22 mA cm –2 at an overpotential of −0.2 V. Fu et al synthesized Pd nanomeshes assembled with branchlike Pd NPs for ECC to CO . The electrochemical conversion from CO 2 to tunable syngas can be realized within a range of applied potential from −0.5 to −0.9 V vs RHE.…”

Electrochemical Reduction of Carbon Dioxide: Recent Advances on Au-Based Nanocatalysts

“…As a result, it is imperative to develop remarkable electrocatalysts which significantly speed up the reaction rate and regulate the reaction selectivity toward the target products [16,17]. To date, different types of metal-based electrocatalysts such as Au [18][19][20][21][22][23], Cu [24][25][26][27][28][29][30][31][32][33][34][35][36], Pd [37][38][39][40][41][42][43][44][45][46], Ag [47][48][49][50][51][52][53][54], Bi [32,[55][56][57][58], Sn [59][60][61][62][63] and Co [64]...…”