Chromium-Ruthenium Oxides Supported on Gamma-Alumina as an Alternative Catalyst for Partial Combustion of Methane

Abstract

Catalyst screening of γ-Al2O3-supported, single-metal and bimetallic catalysts revealed several bimetallic catalysts with activities for partial combustion of methane greater than a benchmark Pt/γ-Al2O3 catalyst. A cost analysis of those catalysts identified that the (2 wt%Cr + 3 wt% Ru)/γ-Al2O3 catalyst, denoted as 2Cr3Ru/Al2O3, was about 17.6 times cheaper than the benchmark catalyst and achieved a methane conversion of 10.50% or 1.6 times higher than the benchmark catalyst based on identical catalyst weights. In addition, various catalyst characterization techniques were performed to determine the physicochemical properties of the catalysts, revealing that the particle size of RuO2 became smaller and the binding energy of Ru 3d also shifted toward a lower energy. Moreover, the operating conditions (reactor temperature and O2/CH4 ratio), stability, and reusability of the 2Cr3Ru/Al2O3 catalyst were investigated. The stability test of the catalyst over 24 h was very good, without any signs of coke deposition. The reusability of the catalyst for five cycles (6 h for each cycle) was noticeably excellent.

Mixed RuxIr1−xO2 Supported on Rutile TiO2: Catalytic Methane Combustion, a Model Study

“…From these surface science studies it is quite surprising that pure RuO 2 is active at all in methane combustion. But the observed activity of RuO 2 is consistent with a recent study where RuO 2 supported on Gamma Alumina was discussed as alternative catalyst for methane combustion [40] …”

“…But the observed activity of RuO 2 is consistent with a recent study where RuO 2 supported on Gamma Alumina was discussed as alternative catalyst for methane combustion. [40] Pure RuO 2 (110) is, however, known to be an excellent catalyst in the CO oxidation reaction, [22] while on IrO 2 (110) the adsorption of CO was found to be much stronger than on RuO 2 . [41] In fact, RuO 2 has shown to be more active in the CO oxidation than IrO 2 .…”

Direct conversion of methane to value-added hydrocarbons using hybrid catalysts of Ni/Al2O3 and K–Co/Al2O3

“…In fact, the CH 4 : O 2 ratio of 2 is the stoichiometric number of the partial oxidation of the methane reaction that generally produces high CO and H 2 , 15 which further react to produce light hydrocarbons. 43 In the current study, the amount of oxygen used in the feed was lower than that of methane because the complete oxidation of methane was favored, 44 and there were safety concerns due to the flammability limit 45 and explosion risk in the reactor.…”