Tunable Electronic Metal–Support Interactions on Ceria-Supported Noble-Metal Nanocatalysts in Controlling the Low-Temperature CO Oxidation Activity

Abstract

A fundamental study on the metal−support interactions of supported metal catalysts is of great importance for developing heterogeneous catalysts with high performance, is still attracting and challenging in many heterogeneous catalytic reactions. In this work, we report the catalytic performances of CeO 2 -supported noble-metal catalysts among single atoms, subnanoclusters (∼1 nm), and nanoparticles (2.2−2.7 nm) upon low-temperature CO oxidation reaction between 50 and 250 °C. The subnanoclusters and nanoparticles of Ru, Rh, and Ir showed much higher activities than those of the single atoms, while a Pd single-atom catalyst was more active than Pd subnanoclusters and nanoparticles. According to the results of multiple ex situ and in situ characterizations, the much different activities of Ru, Rh, Ir, and Pd were derived from the alterable electronic metal−support interactions (EMSI), which determine the concurrent reaction pathway including the famous Mars van Krevelen mechanism and carbonate−intermediate route on the most active metal sites of M δ+ (0 < δ < 1) for Ru, Rh, and Ir and Pd 2+ for Pd. Also, the moderate EMSI of CeO 2 -supported Rh subnanoclusters furthest benefited activation of the adsorbed CO molecule and ensured it the highest activity among CeO 2 -supported Ru, Rh, and Ir catalysts with similar metal deposit sizes.

Insight into the Crystal Structures and Surface Property of Manganese Oxide on CO Catalytic Oxidation Performance

“…Exploration to cheaply and efficiently complete the reaction between CO and O 2 to generate CO 2 has attractive potential for the treatment of toxic CO waste gas. − Fortunately, some non-noble oxide can serve as catalysts to effectively promote the reaction under mild conditions at low cost. As a typical heterogeneous reaction, CO catalytic oxidation mainly occurs at the surface and interface of catalysts. − Accordingly, the design and synthesis of oxide catalysts with a higher specific surface area and a more active interface become the key to improve their catalytic performance. , MnO 2 nanomaterials have been researched as a potential catalyst for this heterogeneous reaction due to their large surface and high activity.…”

Visible-Light Driven CO2 Reduction to CO by Co3O4 Supported on Tungsten Oxide

“…For another, the photocatalytic activity of 1Co/W was about 5 times (higher than 4 times) than that of 1Co/W-Mix. And the TON of 1Co/ W (184) was much higher (about 5.75 times) than that of 1Co/W-Mix (32). Hence, except for the exposure of surface cobalt active sites, there may be some more important elements that cause the high performance of 1Co/W.…”

“…Supported catalysts with anchoring of the active components on the surface of supports are widely used in heterogeneously industrial catalysis (e.g., Fischer-Tropsch synthesis, CO 2 hydrogenation, and CO oxidation). − Metal oxides are discovered to be impressive candidates for support materials, such as Al 2 O 3 , SiO 2 , TiO 2 , CeO 2 , ZrO 2 , and so on. − The choice of active components depends on the type of catalytic reactions. In general, an eligible support is conducive to disperse active species against their agglomeration, and plentiful interfacial active sites benefiting the adsorption and activation of reactants can be fabricated in supported catalysts as well. , What is more, interfacial interaction between surface active components and oxide support plays crucial roles in dominating the chemical and electronic properties of the supported catalysts and the surface chemistry in the catalysis process .…”

Ni–Cu Alloy Nanoparticles Confined by Physical Encapsulation with SiO2 and Chemical Metal–Support Interaction with CeO2 for Methane Dry Reforming

“…The fabrication of sintering- and carbon-free Ni catalysts is thus a difficult task for stable MDR. Size effect, metal–support interaction (MSI), and confinement effect in catalysts are demonstrated, positively enhancing MDR performance, retarding Ni sintering, and reducing carbon deposition. − Xiao et al exsolved Ni nanoparticles from Ni x Ce 1– x O 2 ; the Ni nanoparticles with size of 4 nm were uniformly dispersed on CeO 2 , yielding Ni–ceria interfaces with MSI. The synergistic activation of CH 4 and CO 2 at the interfaces stabilized 20% CH 4 conversion at 723 K for 240 h, exhibiting resistances of carbon and sintering .…”