Transient drift spectroscopy for the determination of the surface reaction kinetics of CO2 methanation

Abstract

Abstract--Transient experiments were applied to the study of the adsorbed CO intermediate, (CO),,, formed during the CO2 methanation reaction on a 2% Ru/TiO2 catalyst at 383 K.Step-up experiments showed that the (CO),, formation steps are inhibited by H20 and enhanced by H 2.Step-down experiments showed that the (CO),, hydrogenation is not influenced by the partial pressure of water. Based on the fact that water inhibits the overall CO 2 methanation, it is deduced that the rate limiting process in the overall reaction is (CO),, formation.

Comparative Study of the Electrochemical Promotion of CO2 Hydrogenation over Ru‐Supported Catalysts using Electronegative and Electropositive Promoters

“…The observed electrophobic behavior (@r/@U WR > 0) for the methanation reaction and the observed electrophilic behavior (@r/@U WR < 0) for the RWGS reaction (Figures 2 and 3) is consistent with the rules of chemical and electrochemical promotion. [37,38] Indeed, as already reported in our previous study [45] and other recent studies, [11,12,47,48] and as shown in Figure 4, under the gas conditions of Figure 2, the rate of the methanation reaction has a positive order in reactant D (H 2 , reaction order ca. 1) and negative order in reactant A (CO 2 , reaction order near À1); thus, the promotional rules predict electrophobic behavior (@r/@U WR > 0), as experimentally observed (Figures 2 and 3).…”

Nickel@Siloxene catalytic nanosheets for high-performance CO2 methanation

“…6c) and was ascribed to a surface formate species (HCO 2 − ) 47,48 ; this assignment is supported by an additional peak observed at 2814 cm −1 (Fig. 6d) 11,49 . It is noteworthy that the peak intensity of this formate species is much higher than that of the carbonate species.…”

In-situ surface and gas phase analysis for kinetic studies under transient conditions The catalytic hydrogenation of CO2

“…A schematic representation is given by Marwood et al [7]. Approximately 0.06-0.08 g of the sample was placed in the sample holder of the DRIFTS cell.…”

“…These ordered structures are stabilized by hydrogen and destroyed by water during the transient hydrogenation experiments. It has been shown previously [7] that within a certain hydrogen and water concentration range (5-20% H 2 and PR2o = 2.6-12.3 mbar), the hydrogenation of (CO) a exhibits a first-order dependence on the carbon monoxide surface coverage (Eq. (5)).…”