Aerosol-Assisted Synthesis of Metal–Organic Framework-Derived Hybrid Nanomaterials for Reverse Water–Gas Shift Reaction

Abstract

A continuous aerosol route is demonstrated for the gas-phase synthesis of the copper-based metal–organic framework (Cu-MOF) supported on CeO2 nanoparticle clusters, which can be used to fabricate MOF-derived Cu@CeO2 hybrid nanomaterials for the catalysis of reversed water–gas shift reaction (RWGS). The results show that both metal surface area and metal dispersion were enhanced by decreasing the Cu/Ce atomic ratio of the hybrid material. Incorporation of the CeO2 nanoparticle cluster enhanced both activity and stability of the MOF-derived nanostructured catalysts. In addition to high selectivity and sufficient operation stability toward RWGS, a superior high catalytic activity under a relatively low-temperature operation was achievable (i.e., TOFCO2 = 0.1635 s–1 at 400 °C) in comparison to the reported values in the literature. The present development for MOF-derived nanostructured materials produced by using an aerosol-based evaporation-induced self-assembly method opens up opportunities for the design of nanostructured catalysts useful for a variety of applications in CO2 capture and utilization.

Recent Advances in Hydrogenation of CO2 to CO with Heterogeneous Catalysts Through the RWGS Reaction

“…Tsai et al [58] reported a hybrid Cu@CeO 2 catalysts with a MOF-derived nanostructured features prepared by aerosolassisted approach. A superior high catalytic activity (TOF CO2 = 0.1635 s À 1 ) was achieved under a flow of CO 2 /H 2 (1/3) a relatively low-temperature (380 °C).…”

“…Tsai et al [58] . reported a hybrid Cu@CeO 2 catalysts with a MOF‐derived nanostructured features prepared by aerosol‐assisted approach.…”

Microfluidic‐Aerosol Hyphenated Synthesis of Metal–Organic Framework‐Derived Hybrid Catalysts for CO2 Utilization

“…[47] Briefly, CO 2 is adsorbed onto the basic sites (Cu-Ce-O or Cu-Al-O interface) of support (CeO 2 Or Al 2 O 3 ) surface via acid−base interaction under sufficient reaction temperature; then, the adsorbed CO 2 is reduced to CO and subsequently oxidized the metallic Cu to Cu x O; next, the H 2 molecule is adsorbed onto Cu (Cu x O) surface and reacted with lattice oxygen to form H 2 O which results the reduction Cu x O to metallic Cu. [47] Overall, the positive synergistic effect between Cu and support interface (Cu−Ce−O or Cu−Al−O) improves the redox capability of Cu@Support hybrid catalyst in RWGS reaction, accelerating the oxidation of Cu by CO 2 and the reduction of Cu x O by H 2 . In the present case, the 0.2Cu-Ce@Al 2 O 3 catalyst showed better performance which is likely due to the presence of both the active sites, namely, Cu−Ce−O and Cu−Al−O interfaces.…”

“…[38,42] On the other hand, aerosol-based synthesis is another attractive route, [44][45][46] by which MOF and its derived material can be continuously and rapidly produced (i.e., via direct gas-phase thermal treatment) with controlled particle size, shape, and morphology without applying any purification techniques. [47] Hence, it is expected that combining the microfluidic-based continuous flow method with the aerosolbased synthetic technique can produce MOFs and MOF-derived products efficiently.…”

“…[60][61][62][63][64] In this study, HKUST-1, a copperbased MOF with high porosity and surface area, is chosen to fabricate Cu-based hybrid catalysts for RWGS reaction. [47] As for the carrier, we choose alumina and ceria nanopowders to improve the dispersion of copper metal and discuss the influence of different carrier types on the particle size distribution and metal dispersion. [65][66] It is to be noted that this is the first study, to our knowledge, reporting the hyphenation of microfluidic-and aerosol-based synthesis, in combination with real-time differential mobility analysis of MOF-derived hybrid nanostructured products.…”