Highly Dispersed Antisintering Cu Catalyst from Cu–Al Spinel Oxide Obtained by Using Surface Solid Reaction for Reverse Water–Gas Shift

Abstract

Inhibiting the sintering of Cu-based catalysts for CO 2 reverse water−gas shift (RWGS) reaction is still a great challenge. Herein, Cu−Al spinel supported on Al 2 O 3 was prepared by a surface solid reaction and used as a precursor to obtain Cu particles with high dispersions and high stabilities. Due to the high dispersions of Cu cations in Cu−Al spinel, strong chemical interactions between Cu particles and newly generated Al 2 O 3 , and the isolation effects of Al 2 O 3 particles, Cu particles derived from Cu−Al spinel exhibited smaller sizes after H 2 reduction, excellent activities, and 300 h stabilities for RWGS reactions. However, Cu particles obtained from the supported CuO precursor showed much larger particle sizes (>70 nm) and inferior activities and stabilities for CO 2 reverse water−gas shift reaction. This study made a successful attempt to enhance the activities and stabilities of Cu-based catalysts through changing the oxide precursor.

Stabilized inverse Y2O3/Cu interfaces boost the performance of the reverse water–gas shift reaction

“…In addition, it is worth noting that the adsorption and activation of CO 2 were confirmed to exhibit important effects on boosting the catalytic performance in the RWGS reaction. 16–22 Therefore, the adsorption and activation of CO 2 were further studied using various techniques. As shown in Fig.…”

“…12–15 Stable Cu-oxide interfaces can be maintained by decreasing Cu loading to fabricate highly dispersed Cu sites, designing reducible oxide shells to obtain the SMSI effect and synthesizing Cu-based catalysts with special spinel structures. 6,16–22 However, these methods inevitably lead to fewer initial or exposed active Cu species, resulting in unsatisfactory catalytic activity. 6,16–22 It has been reported that the active metals of inverse model catalysts (support oxides embedded in bulk active metals) are sintered in the initial state, which can greatly avoid their further agglomeration during the reaction process.…”

“…6,16–22 However, these methods inevitably lead to fewer initial or exposed active Cu species, resulting in unsatisfactory catalytic activity. 6,16–22 It has been reported that the active metals of inverse model catalysts (support oxides embedded in bulk active metals) are sintered in the initial state, which can greatly avoid their further agglomeration during the reaction process. 23–26 Therefore, inverse catalysts possess abundant metal–oxide interfaces, effectively ensuring their stability, which exhibit great potential to overcome the deactivation of Cu-based catalysts in the RWGS reaction.…”

Polyoxometalate-HKUST-1 composite derived nanostructured Na–Cu–Mo2C catalyst for efficient reverse water gas shift reaction

“…N 2 O titration analysis is an effective method to estimate the Cu metal dispersion (Dis Cu ) as reported previously. 53,54 Based on the following reactions during the N 2 O titration method followed by H 2 consumption during H 2 pulse reduction, we can estimate that the Dis Cu ∝ H 2 consumed after N 2 O titration:2Cu + N 2 O ↔ Cu 2 O + N 2 Cu 2 O + H 2 ↔ 2Cu + H 2 O…”

Regulating the Redox Cycle of Highly Dispersed CuMn2O4 on SiO2 for Toluene Catalytic Combustion

“…(AB 2 O 4 ) type oxides are considered to be promising catalysts for the catalytic oxidation of VOCs due to the electron tunability of their metal elements, which can effectively improve the redox capacity and oxygen mobility of catalysts. − The modification of spinel catalysts generally revolves around the construction of defects, A and B site element replacement, morphological design, and other methods. − In recent years, it has been found that controlling the dispersion state and crystalline structure of the spinel to modulate the electronic structure of the metal ions can effectively advance the redox cycle and active site status in spinel catalysts, and impact the behavior of the reactants on the surface of the catalyst, so as to control the reaction activity . Enhancing the dispersion of the spinel is a common choice to modulate catalytic activity.…”