Dry Reforming of Shale Gas and Carbon Dioxide with Ni‐Ce‐Al₂O₃ Catalyst: Syngas Production Enhanced over Ni‐CeO_x Formation

Abstract

The dry reforming of shale gas (methane and ethane with an average ratio of 4 : 1) with carbon dioxide (DRS) is considered to be a promising way to produce syngas, which widens the utilization of shale gas and mitigates carbon dioxide emission. In this paper, Ce modified Ni‐based catalysts were developed and the corresponding catalytic performances for DRS were investigated with a fixed bed reactor. Results showed that the catalyst containing 5 wt% of Ni and 5 wt% of Ce performed a best catalytic effect, including the selectivity of syngas and the carbon resistance performance, which is due to the good metal dispersion, strong interaction between Ni and Ce, and the formation of Ni‐CeOx solid solution. The electron transfer between Ni and Ce, substitution of Ni for Ce, and the sequential oxygen vacancies or defects, play significant roles in activating CH4, C2H6 and CO2. The conversion of reactant gas increased with temperature, while the selectivity of syngas is little affected with temperature. In addition, the desired catalyst containing 5 wt% of Ni and 5 wt% of Ce showed good stability in the long‐time operation, which indicates that the Ce modified Ni‐based catalyst is a promising one for the dry reforming of shale gas.

Ni-Ru supported on CeO2 obtained by mechanochemical milling for catalytic hydrogen production from ammonia

“…This can be attributed to a relationship between oxygen vacancies and Ce 3+ presence, as well as enhanced electron transfer capacity. 83 The increase in the reduced form of ceria also correlates well with the increase in the intensity of the band related to defects in the structure of ceria of the Raman spectra. It has been reported in the literature that the interaction between oxygen vacancies in the support and the active phase facilitates the recombinative desorption of N atoms, achieving higher catalytic performance in the decomposition of NH 3 , due to the increase in electron density that could be transferred from the basic sites of the support at the surface of the active phase.…”

Insights into Nickel-Based Dual Function Materials for CO2 Sorption and Methanation: Effect of Reduction Temperature

“…The Ce 3+ proportion in the catalysts reduced at 300 and 500 °C declines to 25.31 and 23.62%, respectively. This should be ascribed to the electron transfer among the different redox couples (eqs and ), and this will promote NiO reduction . The decrease in Ce 3+ proportion at higher temperatures should indicate that the catalyst reduction process consumes more oxygen vacancy defects.…”

“…This should be ascribed to the electron transfer among the different redox couples (eqs 8 and 9), and this will promote NiO reduction. 56 The decrease in Ce 3+ 2+ first, and the further reduction of Ni 2+ to metallic Ni occurs subsequently. Moreover, the reduction of Ni 2+ to metallic Ni favors a higher temperature, as evidenced by the increase in the ratio of metallic Ni from 3.93 to 10.23% with the increasing temperature from 300 to 650 °C.…”

Effect of Ce doping on the catalytic performance of xNiCeOy@SiO2 catalysts for dry reforming of methane

“…The proportion of surface Ce 3+ species is shown in Table 6. It is well‐known that the Ce 3+ concentration is directly proportional to the amount of oxygen vacancies or defect sites in the catalyst, which can transfer adsorbed O * species to Ni active components to oxidize CH x * species so as to further enhance the rate of carbon gasification reaction to improve the stability of the catalysts 12,28,29 . Therefore, the most stable catalyst 10NiCeO y @SiO 2 with the highest Ce 3+ proportion of 45.2% has more oxygen vacancies on the catalyst surface to help eliminate the carbon deposits, thereby improving the stability of the catalyst.…”