Highly Efficient Layered Double Hydroxide-Derived Bimetallic Cu–Co Alloy Catalysts for the Reverse Water–Gas Shift Reaction
Kwang Young Kim, Wonsik Jang, Woo Jin Byun, Ji Young Lee, Ji Young Lee, Miri Kim, Ju Hyeong Lee, Ju Hyeong Lee, Geun Bae Rhim, Min Hye Youn, Dong Hyun Chun, Seok Ki Kim, Seungho Cho, Jae Sung Lee, Jae Sung Lee
Abstract
Bimetallic alloy catalysts with finely controlled composition and atomic mixing of the two active metals are vital for maximizing their synergistic effect in enhancing catalytic performances. Herein, we report the design and synthetic strategy of bimetallic Cu–Co alloy catalysts well dispersed on Al 2 O 3 from a CuCoAl-layered double hydroxide (LDH) for boosting the reverse water–gas shift (RWGS) performance by controlling the composition and textural properties of Cu–Co alloy particles. An optimized Cu 9 Co 1 /Al 2 O 3 catalyst exhibits a remarkably high CO 2 to CO conversion rate (∼0.247 mol h –1 g cat –1 ) with ∼99.4% of CO selectivity at a relatively low reaction temperature of 400 °C, which outperforms a monometallic Cu/Al 2 O 3 catalyst and a reference Cu 9 Co 1 /Al 2 O 3 catalyst prepared by a conventional impregnation method. A combined experimental and theoretical study reveals that the superior activity of the Cu 9 Co 1 /Al 2 O 3 catalyst is attributed to two factors: (i) a modified electronic structure due to the Cu–Co alloy formation that facilitates CO 2 activation and CO desorption and (ii) formation of well-dispersed alloy nanoparticles by using LDHs as the catalyst precursors.