Facile and Eco-Friendly Approach To Produce Confined Metal Cluster Catalysts

Abstract

Zeolite-supported metal nanocluster catalysts have attracted significant attention due to their broad application in heterogeneously catalyzed reactions. The preparation of highly dispersed metal catalysts commonly involves the use of organic compounds and requires the implementation of complicated procedures, which are neither green nor deployable at the large scale. Herein, we present a novel facile method (vacuum-heating) which employs a specific thermal vacuum processing protocol of catalysts to promote the decomposition of metal precursors. The removal of coordinated H 2 O via vacuum-heating restricts the formation of intermediates (metal-bound OH species), resulting in catalysts with a uniform, metal nanocluster distribution. The structure of the intermediate was determined by in situ Fourier transform infrared, temperatureprogrammed decomposition, and X-ray absorption spectroscopy (XAS) measurements. This alternative synthesis method is eco-friendly and costeffective as the procedure occurs in the absence of organic compounds. It can be widely used for the preparation of catalysts from different metal species (Ni, Fe, Cu, Co, Zn) and precursors and is readily scaled-up.

Sustainable biofuel synthesis from non-edible oils: a mesoporous ZSM-5/Ni/Pt catalyst approach

“…Similarly, the absorption band around 3640 cm −1 is ascribed to the O–H stretching vibration of Brønsted acid OH groups from the bridging Si(OH)Al in the zeolite framework. 51,52 Lastly, the band at 662 cm −1 is assignable to Si–O–M where M is the exchangeable Ni + ion metal species. All three types of zeolites, namely Ni/Pt-ZSM-5, Ni/Pt/MCM-48, and Ni/Pt-H-beta, have hydrophilic properties which cause them to absorb water when exposed to the atmosphere.…”

Selective CO2hydrogenation over zeolite-based catalysts for targeted high-value products

“…Na + , NH 4 + , H + ), which in turn generated Brønsted acid sites (BASs) if they are counterbalanced by H + . 122,123 Due to the conned space around the active sites and the restricted access to and exit from the internal surface, zeolites are widely use as shape-selective catalysts in variety of chemical reactions, such as CO 2 hydrogenation, 57 synfuels production, 124 oil renery, [125][126][127][128][129][130] biomass pyrolysis, 131,132 etc. FTS pathways for hydrogenation of CO 2 to selectively produce methanol, [40][41][42] ethanol, 43,44 dimethyl ester (DME), [45][46][47] LPG, [48][49][50][51] olefins, 48,52-56 aromatics, [57][58][59] and other hydrocarbons.…”

“…Na + , NH 4 + , H + ), which in turn generated Brønsted acid sites (BASs) if they are counterbalanced by H + . 122,123 Due to the confined space around the active sites and the restricted access to and exit from the internal surface, zeolites are widely use as shape-selective catalysts in variety of chemical reactions, such as CO 2 hydrogenation, 57 synfuels production, 124 oil refinery, 125–130 biomass pyrolysis, 131,132 etc.…”

Toward High‐Performance Hydrogenation at Room Temperature Through Tailoring Nickel Catalysts Stable in Aqueous Solution

“…[14] Moreover, simple strategies can be adopted to regulate the structure of Ni-based catalysts, resulting in activities comparable to those of noble-metal-based catalysts. [15,16] As a green solvent for catalytic reactions, water is easy to access, inexpensive, nontoxic, and pollution free. [17] Consequently, water utilization in catalytic reactions has garnered significant attention in recent years.…”