(521df) Synthesis and characterization of Ceria-supported metal (M)/metal oxide (MOx)catalysts by novel one pot-chemical vapor deposition (OP-CVD) method

In the past, many processes viz. impregnation, precipitation, colloidal, and atomic layer deposition have been put into practice for the synthesis of metal (M) or metal oxide (MOx) over support materials. Since most of these methods involve liquid-solid phase interactions, poor metal-support interaction may lead to random M/MOx loading and agglomerations. Overcoming the drawbacks of the existing methods, the present study aims to develop ceria-supported M/MOx (M=3d group transition metals) catalysts via onepot chemical vapor deposition (OP-CVD) approach hypothesizing different metal deposition pathway via gas-support actions. Simple procedures, uniform distribution of M/MOx from the gas phase synthesis, and economic feasibility were the main motivation behind building the OP-CVD technique. The synthesis process involves three basic steps: (i)premixing; (ii)vaporization/dispersion; and (iii)decomposition as shown in Fig.1(a). Unique organometallic precursors for each metal were studied for its structure and chemical properties. Thermogravimetric (TGA) analysis was performed to understand the thermal effects and further determine the synthesis conditions. The prepared catalysts were characterized using XRD, Raman spectroscopy, BET, ICP-MS, STEM-EDS (Fig.1(b)) and TEM to understand its physicochemical properties. Improved characteristics via the OP-CVD method proves that selecting an appropriate organometallic precursor and favorable synthesis conditions make this catalyst designing approach simple and efficient, corroborating its vast future scope.

Acknowledgements

The authors acknowledge funding support from: National Science Foundation (NSF-CBET2050824) and National Science Foundation (NSF CHE 2102299). This research used
the beamline 28-ID-1 of the National Synchrotron Light Source II (NSLS-II) and the Materials Synthesis and Characterization Facility of Center for Functional Nanomaterials (CFN), which are U.S. Department of Energy (DOE) Office of Science User Facilities at Brookhaven National Laboratory under Contract No. DE-SC0012704.

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