Selective CO<sub>2</sub> Reduction Electrocatalysis Using AgCu Nanoalloys Prepared by a “Host–Guest” Method
Marta Śliwa, Hao Zhang, Jiaxin Gao, Benjamin O. Stephens, Andrew Patera, David Raciti, Paul D. Hanrahan, Zoey Warecki, Daniel L. Foley, Kenneth J. T. Livi, Todd Brintlinger, Mitra L. Taheri, Anthony Shoji Hall, Thomas J. Kempa
Abstract
Multimetallic nanoalloy catalysts have attracted considerable interest for enhancing the efficiency and selectivity of many electrochemically driven chemical processes. However, the preparation of homogeneous bimetallic alloy nanoparticles remains a challenge. Here, we present a room-temperature and scalable, host–guest approach for synthesis of dilute Cu in Ag alloy nanoparticles. In this approach, an ionic silver bromide precursor harboring exogenous Cu cations is reduced to yield ∼20 nm diameter AgCu alloy nanoparticles wherein the % Cu loading can be tuned precisely. AgCu nanoparticles with a 5% nominal loading of Cu exhibit peak activity (−0.23 mA/cm 2 normalized partial current density) and selectivity (83.2% faradaic efficiency) for CO product formation from electrocatalytic reduction of CO 2 at mild overpotentials. These AgCu nanoalloys exhibit a higher mass activity compared to Ag- and Cu-containing nanomaterials used for similar electrocatalytic transformations. Our host–guest synthesis platform holds promise for production of other nanoalloys with relevance in electrocatalysis and optics.