{'fraction_non_alphanumeric': 0.04906333630686887, 'fraction_numerical': 0.010704727921498661, 'mean_word_length': 5.0978260869565215, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 5, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Selective Methane Functionalization via Oxyhalogenation over Supported Noble Metal Nanoparticles

This article investigates SiO2-supported Ru-, Pt-, Ir-, Rh-, and Pd-based catalysts (1 wt % metal loading) as new catalytic systems for the oxychlorination and oxybromination of methane, both pivotal steps in the halogen-mediated production of commodities from natural gas. Furthermore, this article provides insights into the structure–performance relationships and mechanism of these reactions as a function of the metal and the hydrogen halide. In-depth characterization of the equilibrated catalysts by X-ray diffraction, electron microscopy, Raman, and X-ray photoelectron spectroscopies demonstrate a fast restructuring of the starting oxide nanoparticles into metallic, metal silicide, or metal halide phases. The oxychlorination activity, which decreases in the order: Ru/SiO2 > Pt/SiO2 > Ir/SiO2 > Rh/SiO2 ≈ Pd/SiO2, is enhanced in the presence of metal oxides, while the activity order in oxybromination: Ru/SiO2 ≈ Ir/SiO2 ≈ Pd/SiO2 > Pt/SiO2 > Rh/SiO2 is less dependent on the phase composition. The highest s...