Metal-Loaded Hollow Carbon Nanostructures as Nanoreactors: Microenvironment Effects and Prospects for Biomass Hydrogenation Applications

Abstract

Over the past decade, metal-loaded hollow carbon nanostructures have been hailed as man-made nanoreactors (MHC nanoreactors) for extensive applications in dealing with energy and environmental issues due to their tailorable structure and electronic properties. Unlike conventional reports of hollow nanostructures with regard to synthetic methodologies or structural properties, a distinctive viewpoint on the microenvironment effects of MHC nanoreactors, i.e., metal–support interaction effect, reactant enrichment effect, molecular sieving effect, spatial compartmentation effect, and metal stabilization effect, is highlighted herein from this perspective. Furthermore, to emphasize the great potential of MHC nanoreactors in constructing a sustainable energy system to achieve a greener modern lifestyle, a review of the applications of MHC nanoreactors in the hydrogenation of typical biomass-derived molecules is presented. Additionally, prospects for broader biomass valorization applications of MHC nanoreactors, i.e., in situ hydrogen source-assisted hydrogenation, hydrogenation-involved cascade-type reactions, hydrogenation product distribution modulation, stability prolongation and recyclability enhancement, are forecasted. Toward the end of this paper, some feasible suggestions are further proposed for the enhancement of the catalytic reactivity, selectivity, stability, and sustainability of MHC nanoreactors in biomass hydrogenation, with a sincere expectation to contribute to the development of a highly efficient biomass refining system.

Advanced Carbon‐Based Nanocatalysts and their Application in Catalytic Conversion of Renewable Platform Molecules

“…Hitherto, people have explored a variety of structural factors to regulate the catalyst performance including spherical curvatures, wall thickness and so on [112,125–127,132,136] . By precisely tuning the structural factors, the catalytic performance can be largely optimized [126] .…”

Copper and palladium bimetallic sub-nanoparticles were stabilized on modified polyaniline materials as an efficient catalyst to promote C–C coupling reactions in aqueous solution

“…Metal-loaded carbon nanostructure composite materials can be recovered from reactions through a simple separation method, which greatly reduces the reaction cost and has become one of the hot topics of current research. 1,2 Since the C-C coupling reaction was first proposed, it has greatly promoted the development of fine organic chemistry synthesis. [3][4][5] Various natural products, sensors, dyes, and drugs have been synthesized through simple routes.…”

Hydrogenation of furfural to furfuryl alcohol over MOF-derived Fe/Cu@C and Fe3O4/Cu@C catalysts

“…21–23 Thus, during the design of catalysts for furfural hydrogenation with alcohol solvents and under hydrogen reaction conditions, attention should be paid not only to the catalytic activity of the center, but also to the effects of the catalytic hydrogenation route. 24–26…”

“…[21][22][23] Thus, during the design of catalysts for furfural hydrogenation with alcohol solvents and under hydrogen reaction conditions, attention should be paid not only to the catalytic activity of the center, but also to the effects of the catalytic hydrogenation route. [24][25][26] Recently, great attention has been paid to crystalline materials, specifically, metal-organic frameworks (MOFs) with periodic network structures that are composed of metal ions or metal clusters and multidentate organic ligands and obtained through self-assembly. 27,28 These self-assembled coordination polymers can form one-, two-or threedimensional porous structures, and possess large pore sizes, large specific surface areas, highly ordered pore structures, and controllable pore sizes.…”