Exsolution–Dissolution of Supported Metals on High-Entropy Co₃MnNiCuZnO_x: Toward Sintering-Resistant Catalysis

Abstract

Herein, in situ generation of CuCoNi nanoalloys over a high-entropy oxide Co 3 MnNiCuZnO x matrix has been employed to generate a sintering-resistant metal-oxide interface for the CO 2 hydrogenation reaction. The high-entropy Co 3 MnNiCuZnO x catalyst with a single reverse spinel structure was synthesized by a mechanochemical redox-based process and thermal treatment just at 600 °C. Interestingly, the entropy-driven force allows the exsolution and dissolution of CuCoNi alloys under reductive and oxidative recyles, which results in the dynamics confinement of the supported metals. With high temperature (500 °C) CO 2 hydrogenation as a model reaction, the restriction of CuCoNi nanoparticles over a high-entropy Co 3 MnNiCuZnO x matrix guaranteed long-term thermal stability (>100 h). In comparison, binary CoMnO x as a control catalyst deactivated in 10 h. This high-entropy stabilization may inspire a number of sintering-resistant catalysts in the near future.

Two-Dimensional High-Entropy Metal Phosphorus Trichalcogenides for Enhanced Hydrogen Evolution Reaction

“…The valence-state proportions of each metal are summarized in Table S4. The spin–orbit 2p 3/2 and 2p 1/2 orbitals of Co modes are observed at binding energies of 779.76 and 795.06 eV (Figure a). − In both CoPS 3 and Co 0.6 (VMnNiZn) 0.4 PS 3 NSs, the existence of a doublet splitting of the Co 2p peaks is attributed to the oxidation state of Co 3+ (779.66/794.76 eV) and Co 2+ (781.16/796.36 eV), respectively. − In the V 2p spectrum, the mode at 514.18 eV belongs to V 2p 3/2 (V 3+ ) and the mode at 521.98 eV corresponds to V 2p 1/2 (V 3+ ) (Figure b). The adjacent modes at 516.78 eV (V 2p 3/2 ) and 524.68 eV (V 2p 1/2 ) are attributed to the presence of V 4+ .…”

Designing strategies and enhancing mechanism for multicomponent high-entropy catalysts

“…They can be summarized in four categories, which are electrocatalysis (for example, water splitting, fuel cells, metal–air batteries, metal–sulfur batteries, CO 2 electro-reduction, etc. ), 17,123,126 high-temperature gas phase reactions (such as NH 3 decomposition, 127 CO oxidation, 128 CO 2 hydrogenation, 129 methane combustion, 130 etc. ), liquid phase organic reactions, 131,132 and photocatalytic reactions.…”

Nonclassical Strong Metal–Support Interactions for Enhanced Catalysis

“…Combined with redox treatments at elevated temperatures, the entropy stabilization strategy was extended to transition metal catalysts including Zr 0.5 (NiFeCuMnCo) 0.5 O x and Co 3 MnNiCuZnO x . The redox-mediated exsolution–dissolution behavior facilitates creation of oxygen vacancies in HEOs, bringing improved CO 2 hydrogenation performance relative to that of the conventional binary and ternary mixed oxides. , In theory, the entropy stabilization strategy can be more effective in dispersing active species with higher-temperature treatments. The pronounced entropic effects, according to the Gibbs free energy equation (Δ G = Δ H – T Δ S , where Δ G is the Gibbs free energy change, Δ H is enthalpy change, T is temperature, and Δ S is entropy change), may reverse the sintering phenomenon and present finely dispersed, antisinter metal sites via entropy-driven metal–support interactions.…”