Single-Crystalline Mesoporous Palladium and Palladium-Copper Nanocubes for Highly Efficient Electrochemical CO2 Reduction

Abstract

Mesoporous single crystals have unique potential in catalysis, but remain unexplored owing to the enormous synthetic challenge that they pose. Herein, we report a facile soft-template method to prepare palladium (Pd) and Pd alloy nanocubes with single-crystallinity and abundant mesoporosity. The successful formation of these exotic nanostructures essentially relies on the cointroduction of cetyltrimethylammonium chloride as the surfactant template and extra Cl− ions as the facet-selective capping agent under well controlled experimental conditions. Thanks to their large surface areas and penetrating mesoporous channels, our products exhibit a great performance for electrochemical CO2 reduction. The best sample from alloying palladium with copper enables the efficient formate production with high selectivity (90∼100%) over a broad potential range, and great stability even under the working potential as cathodic as −0.5 V versus a reversible hydrogen electrode. These performance metrics are far superior to previous Pd-based materials, and underscore the structural advantages of our products.