Self-supported nanoporous CuNiAl alloy as highly efficient electrocatalyst for nitrobenzene hydrogenation to aniline

Abstract

Electrocatalytic nitrobenzene (NB) hydrogenation with high selectivity, yield and Faradaic efficiency (FE) is an economic and sustainable approach to produce high-purity aniline (BA). However, its implementation is essentially hindered by state-of-the-art Cu-based metallic electrocatalysts, which are of insufficient intrinsic activity and unstable nanostructures, in addition to low FE caused by irrepressibly competitive hydrogen evolution reaction at high overpotential. Herein, we report a self-supported nanoporous CuNiAl alloy as a highly efficient electrocatalyst towards NB hydrogenation reaction. Owing to the incorporation of Ni in intermetallic Al4Cu9(Ni), which is of high intrinsic activity, and the hierarchical nanoporous architecture, which facilitates electron transfer and mass transportation along interconnective metal ligaments and interpenetrative pore channels, self-supported nanoporous CuNiAl electrode exhibits remarkably enhanced NB hydrogenation electrocatalysis for BA product with high selectivity (98%), yield (88.5%) and FE (82.3%) at ultralow operating potential (−0.07 V versus RHE). This nanoporous CuNiAl alloy outperforms some of the best Cu-based nanocatalysts reported previously. This work makes a stride for designing novel low-cost electrocatalysts for high-efficient NB hydrogenation by following composition control and morphology engineering.