Production of Synthesis Gas by Direct Catalytic Oxidation of Methane on Pt{110} (1 × 2) Using Supersonic Molecular Beams

Abstract

The absolute rate of the methane oxidation reaction over Pt{110} was investigated over the temperature range 400-900 K using molecular beams under ultrahigh vacuum (UHV) conditions. It was found that the surface reaction is biphasic, with CO 2 being the major product at <550 K and CO the major product at >600 K. Under our reaction conditions, the reaction products H 2 , CO, and CO 2 were detected. The H 2 O production was below the limit of detectability. The product selectivity to CO and CO 2 can be controlled by varying the beam composition as well as the surface temperature. A mean field coupled differential equation model of the process provides a reasonable description of all the experimental observations, although it does not include a proper description of prompt CO desorption at high surface temperatures.

Theory of Methane Dehydrogenation on Pt{110}(1 × 2). Part I: Chemisorption of CHx(x= 0 −3)

“…The dissociative chemisorption and subsequent decomposition of methane on the reconstructed Pt{110}(1 × 2) surface has been studied extensively using molecular beam techniques, − with a view toward elucidating the mechanism of methane partial oxidation on this surface. − In particular, Watson and co-workers 12,13 were able to identify the products of methane dissociative chemisorption on this surface as a function of surface temperature. In a series of experiments based on temperature-programmed reaction spectroscopy (TPRS), Watson et al , established that methylidyne (CH) is the stable dissociation product at all coverages in the surface temperature range of 300−450 K and that at temperatures above 470 K methylidyne decomposes to adsorbed carbon and gaseous H 2 .…”

Molecular beams and chemical dynamics at surfaces

“…Reactions studied are usually rather simple and include oxidation of NO, CO and methanol on metal surfaces, see e.g., 33 and the partial oxidation of methane leading to synthesis gas. 34 An impressive new machine has been built to study chemical reactions at complex surfaces as reviewed by Libuda and Freund. 35…”

Facile Fabrication of Highly Active Magnetic Aminoclay Supported Palladium Nanoparticles for the Room Temperature Catalytic Reduction of Nitrophenol and Nitroanilines

“…Pd NPs have demonstrated outstanding effectiveness as catalysts for catalytic properties in different organic reactions on chemical and pharmaceutical industries, including hydrogenation and C–C coupling reactions [ 17 , 18 ]. For example, Naghipour et al [ 19 ] reported that Fe 3 O 4 @CS-Schiff based Pd nanocatalysts showed higher catalytic activity for Suzuki-Miyaura and Heck-Mizoroki C–C coupling reactions. Molga et al [ 20 ] reported a palladium on alumina catalyst as being a highly selective homogeneous catalyst for the reduction of 2,4-dinitrotoluene.…”