Promotion of Metallic Catalysts by Metal Oxide Powders in Partial Oxidation of Methane

In this paper, the performance of metallic wire arc spraying (WAS) catalysts, promoted by adding TiO2 and Montmorillonite (K10) powders was investigated in catalytic partial oxidation of methane (CPOM) to syngas. The WAS system is a branch of thermal spraying methods that is commercially used to produce a wide variety of coatings. The high temperature of the arc melts, wires and an atomizing gas breaks-up the molten material on the wires tips and propels it in the form of droplets to prepared catalysts. Low running cost, high spray rates and efficiency make it a good process for the preparation of catalysts. In order to prevent the more sintering of the catalyst structure and to stabilize the active sites, metal oxide is combined with other metal oxides. The catalytic performance of the prepared catalysts show that the CO selectivity and H2 yield were depended on type of the adding TiO2 and K10 promoters and the syngas with a H2/CO ratio of about 2 was obtained for the WAS catalyst with K10 promoted, at 800 and 850 °C. Also, characterization of the WAS catalysts by BET, XRD, SEM and EDX techniques showed that the adsorption curves of the WAS catalysts turned to be of type III, reflecting the enhancement of low affinity of nitrogen to the surface. Additionally, the promoted WAS catalyst has the smallest crystal size (high surface area), which indicates the correlation of crystal size and the catalytic activity.

► The performance of metallic wire arc spraying (WAS) catalysts, promoted by adding TiO2 and Montmorillonite (K10) powders was investigated in catalytic partial oxidation of methane (CPOM) to syngas.
► The WAS system is a branch of thermal spraying methods that is commercially used to produce a wide variety of coatings.
► The high temperature of the arc melts, wires and an atomizing gas breaks-up the molten material on the wires tips and propels it in the form of droplets to prepared catalysts.
► The catalytic performance of the prepared catalysts show that the CO selectivity and H2 yield were depended on type of the adding TiO2 and K10 promoters and the syngas with a H2/CO ratio of about 2 was obtained for the WAS catalyst with K10 promoted, at 800 and 850 °C.
► The characterization of the WAS catalysts by BET, XRD, SEM and EDX techniques showed that the adsorption curves of the WAS catalysts turned to be of type III, reflecting the enhancement of low affinity of nitrogen to the surface.
► The promoted WAS catalyst has the smallest crystal size (high surface area), which indicates the correlation of crystal size and the catalytic activity.