Metal and Metal Oxide Supported on Ordered Mesoporous Carbon as Heterogeneous Catalysts

Abstract

The evolution of model catalyst systems has experienced single-crystal surfaces of different transition metals and different crystal faces, two-dimensional systems with nanoparticles (NPs) deposited on a flat support surface, and threedimensional systems with NPs loaded into the high-surface-area supports such as ordered mesoporous materials. The latter two systems mimic the nanoparticle properties in industrial catalysts. Ordered mesoporous carbon (OMC) materials play unparalleled roles in catalysis, energy storage, adsorption, chromatographic separation, etc. because of their distinctive structure which allows Knudsen diffusion inside mesopores, the dispersion of loaded metals and oxides, and the embedment of metals inside pore walls. In this review, the synthesis routes of OMC-supported metal or metal oxide catalysts, including hard-templating and soft-templating methods, are briefly introduced. Mass transfer inside the mesopores, reactant chemisorption on the metals, discrimination of the different active species, and the catalytic reaction mechanism of the OMC-supported metal or metal oxide catalysts are systemically summarized, with the highlight of advantages in catalysis occurring inside mesopores. Understanding these molecular-dominated factors provides insight into controlling the highly active and selective catalytic reactions and, therefore, the design of industrial catalysts with a long life.

Coupling NiSe2 Nanoparticles with N-Doped Porous Carbon Enables Efficient and Durable Electrocatalytic Hydrogen Evolution Reaction at pH Values Ranging from 0 to 14

“…For three composite catalysts, the catalytic activities of both NC-NiSe 2 -12 and NC-NiSe 2 -48 are inferior to that of NC-NiSe 2 -24, indicating that much higher or lower NiSe 2 coverages do not favor the enhancement of catalytic activity. The above results prove that the incorporation of carbon matrix is essential to enhance the HER activity of NiSe 2 . In addition, the hierarchical pores involved in NC provide rich channels for the efficient transport of active species in the catalytic process of electrocatalysis, thereby significantly boosting the electrochemical performance …”

“…The above results prove that the incorporation of carbon matrix is essential to enhance the HER activity of NiSe 2 . 45 In addition, the hierarchical pores involved in NC provide rich channels for the efficient transport of active species in the catalytic process of electrocatalysis, thereby significantly boosting the electrochemical performance. 46 To understand the intrinsic mechanism of high catalytic activity of NC-NiSe 2 -x, the HER kinetics are further studied by Tafel slopes, where a smaller value is indicative of faster reaction kinetics.…”

Hydroxymethyl-Functionalized Polymer Nanospheres with a Hollow Mesopore Structure for Efficient Acteoside Adsorption

“…Among them, the HPN-2 showed both the largest pore volume (0.37 cm 3 /g) and pore size (3.46 nm). The large pore volume and wide pore were expected to provide accommodate space and pore channels to accommodate and accelerate the diffusion of ACT, and it was beneficial to enhance the adsorption . The results revealed that HPN-2 had the appropriate pore volume and pore size for ACT adsorption.…”

Advances in the Research of Photo, Electrical, and Magnetic Responsive Smart Superhydrophobic Materials: Synthesis and Potential Applications

“…The term "responsive factor" typically refers to specific sensitive substances that undergo changes in response to external stimuli. For instance, photoresponsive materials commonly include polyvinylpyrrolidone [72,73] and TiO 2 , [74,75] electric-responsive materials encompass graphene, [76,77] carbon nanotubes, [78,79] and metal oxides, [80,81] while magnetic-responsive materials comprise Fe, Co, Ni, [82] as well as iron oxides (Fe 3 O 4 , [83,84] γ-Fe 2 O 3 [85,86] ), among others. Noteworthy external environmental stimuli include light, electricity, and magnetism.…”