Dispersed Nickel Boosts Catalysis by Copper in CO₂ Hydrogenation

Abstract

The empirical optimization of the preparation of catalytically active copper-containing catalysts is far more advanced than the fundamental understanding of the catalyst performance because of the structural complexity of the catalysts. Here, we demonstrate the interplay between the catalyst structure and CO 2 hydrogenation on Cu catalysts boosted with nickel species. The nickel dispersion on copper markedly affects the CO 2 dissociation activity and catalytic reaction pathways, thus resulting in distinctive catalytic activity and selectivity attributed to Ni. Specifically, the catalyst incorporating nickel alloyed in copper maximizes the synergy between the two metals and is characterized by conversions close to the thermodynamic equilibrium to CO as a productwith switched off methanationover a wide temperature range. Catalyst performance data, spectra characterizing the catalyst, and theoretical results demonstrate that surface copper with adjacent nickel atoms efficiently activates CO 2 via a redox mechanismwith adsorption of CO being suppressedso that methanation associated with deep hydrogenation of CO is inhibited. The results of this investigation highlight the importance of structures with copper-adjacent-nickel, which appear to offer appealing opportunities for tailoring efficient copper-containing catalysts for CO 2 hydrogenation.

Tuning product selectivity in CO2hydrogenation over metal-based catalysts

“…Inspired by the catalysts with SMSI for weak adsorption of the *CO intermediate to selectively obtain the CO product in CO 2 hydrogenation, it is reasonable that construction of alloyed metal catalysts with variable adsorption of *CO intermediate could be adjusted by the alloyed compositions and supports. 99,100 Recently, alloys of PtCo, NiFe, CuNi and NiAu 16,20,21,101,102 are reported for tuning product selectivity in CO 2 hydrogenation.…”

“…Moreover, addition of promoters/additives might result in the formation of new active sites and interfaces for CO 2 adsorption and transformation. Wang et al 20 More importantly, the simple and uniform structure of Ni-in-Cu catalyst provides a model for mechanism investigation to identify the reaction routes and active sites. By in-situ DRIFTS and XPS studies, the CO 3 2-, CO 2 δand HCO 3species are observed on the catalyst surface, giving decreased signals during the CO 2 hydrogenation, which indicate their important roles as the intermediates for CO formation.…”

“…[2][3][4][5][6] In these transformations, CO 2 hydrogenation over metal-based catalysts is a critical route, but the intricate transformation network and multiple active sites strongly influence the product selectivity. [7][8][9][10][11] In recent years, various chemicals in CO 2 hydrogenation have been achieved, including CO, [12][13][14][15][16][17][18][19][20][21][22] methane, [23][24][25][26][27] methanol, [28][29][30][31][32][33][34][35][36][37] olefins, [38][39][40][41] gasolines, [42][43][44][45][46] aromatics, [47][48][49][50]…”

CO<sub>2</sub> Valorization Reactions over Cu-Based Catalysts: Characterization and the Nature of Active Sites

“…The copper-metal/metal oxide (Cu-MO x ) interface has been characterized as active sites for the CO 2 conversion to chemicals [123,146,186,[189][190][191][192][193]. Theoretical studies on Cu/ZrO 2 catalysts showed high activity for intermediates formation at the Cu-ZrO 2 interface [123,[189][190][191].…”

A Brief Summary of Research Progress on the Application of Rare Earth Materials in Heterogeneous Catalysis

“…选择性 [61] 和常春然等 [62] 用密度泛函理 论(Density Functional Theory, DFT)对稀土金属氧化物活 化甲烷过程中 C-H 键的解离进行了研究, 其中龚学庆 等 [61] [63] 、丁醇 [64] 、巴豆醛 [65] 等高 附加值的化学品, 乙醛/乙醇混合物 aldol 加成的反应路 径如图式 1. [66] .…”