Carbide-Supported Au Catalysts for Water–Gas Shift Reactions: A New Territory for the Strong Metal–Support Interaction Effect

Abstract

Strong metal–support interaction (SMSI) has been regarded as one of the most important concepts in heterogeneous catalysis, which has been almost exclusively discussed in metal/oxide catalysts. Here, we show that gold/molybdenum carbide (Au/MoC x ) catalysts feature highly dispersed Au overlayers, strong interfacial charge transfer between metal and support, and excellent activity in the low-temperature water–gas shift reaction (LT-WGSR), demonstrating the active SMSI state. Subsequent oxidation treatment results in strong aggregation of Au nanoparticles, weak interfacial electronic interaction, and poor LT-WGSR activity. The two interface states can be transformed into each other by alternative carbonization and oxidation treatments. This work reveals the active SMSI effect in metal/carbide catalysts induced by carbonization, which opens a new territory for this important concept.

Catalytic Semi‐Water–Gas Shift Reaction: A Simple Green Path to Formic Acid Fuel

“…In these cases, formiate is the most abundant experimentally observed intermediate because its formation barrier is lower than its dissociation barrier. However, it is difficult to desorb it from the catalyst surface . Ruthenium complexes supported in SILPs have also presented higher activation energies (41–84 kJ mol −1 ) in the WGSR .…”

“…However,i ti sd ifficult to desorb it from the catalyst surface. [56][57][58][59][60][61] Ruthenium complexes supported in SILPs have also presentedh igher activation energies (41-84 kJ mol À1 )i nt he WGSR. [31,32,62] Of note, neither of these catalytic systems were able to yield FA.…”

Recent Advances in the Gold-Catalysed Low-Temperature Water–Gas Shift Reaction

“…In a similar study that demonstrated one of the first reports of strong-metal support interaction (SMSI) between metals and non-oxides, Dong et al showed that Au/MoCx could be formed after treatment of Au/MoO3 with CH4/H2 at 700 °C [49]. The authors demonstrated that the Au/MoCx catalyst could undergo reversible aggregation-redistribution processes upon cycled calcinationcarbonization treatment only, and the Au/MoCx exhibited high activity for the LTS reaction ( Figure 4).…”

“…Summary of the reversibility of the Au/MoO 3 (left) and Au/MoC x (right) phases, showing the difference in dispersion (top) and catalyst activity (bottom) in the low-temperature water-gas shift reaction (LT-WGS). Adapted with permission from the authors of[49]. Copyright 2018 American Chemical Society.…”

Heterogeneous Gold Catalysis: From Discovery to Applications

“…Furthermore, Bao et al prepared highly dispersed Au overlayers supported on molybdenum carbide. Thus, strong interfacial charge transfer between metal and support leads to outstanding activity toward the low-temperature water-gas shift reaction [115]. Zhang et al [116] demonstrated a new concept of wet-chemistry MSI creates AuNPs on titania.…”