Catalytically efficient Ni-NiOx-Y2O3 interface for medium temperature water-gas shift reaction

Abstract

The metal-support interfaces between metals and oxide supports have long been studied in catalytic applications, thanks to their significance in structural stability and efficient catalytic activity. The metal-rare earth oxide interface is particularly interesting because these early transition cations have high electrophilicity, and therefore good binding strength with Lewis basic molecules, such as H2O. Based on this feature, here we design a highly efficient composite Ni-Y2O3 catalyst, which forms abundant active Ni-NiOx-Y2O3 interfaces under the water-gas shift (WGS) reaction condition, achieving 140.6 μmolCO gcat−1 s−1 rate at 300 °C, which is the highest activity for Ni-based catalysts. A combination of theory and ex/in situ experimental study suggests that Y2O3 helps H2O dissociation at the Ni-NiOx-Y2O3 interfaces, promoting this rate limiting step in the WGS reaction. Construction of such new interfacial structure for molecules activation holds great promise in many catalytic systems.

Promoting Molecular Exchange on Rare-Earth Oxycarbonate Surfaces to Catalyze the Water–Gas Shift Reaction

“…Then, the two hydrogen atoms combined to form hydrogen gas . In the associative mechanism, the adsorbed CO molecules reacted with the *OH derived from H 2 O dissociation to form the intermediate, which immediately decomposed to generate CO 2 and H 2 . , A TPSR test is conducted to check the mechanism followed by the 5Cu/Sm 2 O 2 CO 3 sample for catalyzing the WGS reaction. Before verification, we created a realistic catalyst surface through the in situ WGS reaction at 300 °C (Figure a).…”

Weakening the Metal–Support Interactions of M/CeO2 (M = Co, Fe, Ni) Using a NH3-Treated CeO2 Support for an Enhanced Water–Gas Shift Reaction

“…According to the difference of reaction temperature, the WGSR is divided into the high-temperature WGSR (350–450 °C), medium temperature WGSR (250–350 °C), and low-temperature WGSR (190–250 °C) in turn. Considering the thermodynamic resistance caused by the exothermic process at the high-temperature region and kinetic resistance caused by H 2 O activation at the low-temperature region, the catalysts of the WGSR used at medium temperature have been explored and developed widely in recent years. , The choice of active centers mainly concentrates on transition metals such as Fe, , Co, − Ni, , and Cu , after measuring the usage cost in real industrial processing. Taking Co-based catalysts as an example, the combination of the Co species and reducible oxide support of CeO 2 has attracted great attention because of the effective modulation of the interfacial interaction.…”

“…The study of Campbell’s group also pointed out that the stronger the metal nanoparticles were attached to the support, the weaker they were bound with small adsorbates, which might not be conducive to the subsequent progress of the reaction. − Therefore, a rational modulation of the metal–support interaction is important for catalyst design, while a universal method is awaited to develop in view of the challenge of regulating the metal–support interaction without morphology change. Combined with the studies of transition metal-based catalysts, catalysts with outstanding WGSR activity usually possess a high loading amount of transition metal species, which is much higher than the metal amount in noble metal-supported catalysts. ,,, The higher the loading amount is, the weaker the metal–support interaction is and the easier the metallic active sites are generated, which might be directly related with the WGSR activity . Consequently, a weakened metal–support interaction could be expected to promote the Co/CeO 2 interface activity and then increase the utilization efficiency per cobalt site.…”

“…Combined with the studies of transition metal-based catalysts, catalysts with outstanding WGSR activity usually possess a high loading amount of transition metal species, which is much higher than the metal amount in noble metal-supported catalysts. 3,6,34,35 The higher the loading amount is, the weaker the metal−support interaction is and the easier the metallic active sites are generated, which might be directly related with the WGSR activity. 33 Consequently, a weakened metal−support interaction could be expected to promote the Co/CeO 2 interface activity and then increase the utilization efficiency per cobalt site.…”

Ordered Mesopore Confined Pt Nanoclusters Enable Unusual Self-Enhancing Catalysis

“…The EMSI can induce a strong electronic perturbation between ultrafine metal nanoclusters of less than 2 nm and reducible metal oxides, contributing to excellent catalytic activity. − Ma and co-workers have fabricated series of stable supported metal cluster (SMC) catalysts and clarified their advantages in various important catalytic fields. − Designed construction of an appropriate MSI is extremely important to creating SMC catalysts with high stability and activity . The stable interfacial sites with an appropriate MSI allow for excellent performance toward the WGS reaction that is widely used in the chemical industry (e.g., production and purification of H 2 ) due to the accelerated H 2 O dissociation and intermediate transfer. − …”