A review of catalytic partial oxidation of methane to synthesis gas with emphasis on reaction mechanisms over transition metal catalysts

Effects of Synthesis on the Structural Properties and Methane Partial Oxidation Activity of Ni/CeO2 Catalyst

“…Curve fitting allowed The spin orbit components of Ni 2p with shake up features 6 eV above the binding energy of the main peaks, which are typical of Ni(II), are present in both fresh samples. The binding energy of Ni 2p 3/2 , which is located at around 854-855 eV, is characteristic of NiO and Ni(OH) 2 [21]. The binding energy positions of the peaks do not change upon catalytic reaction.…”

“…The feed gas consisting of 2 vol % of CH 4 + 1 vol % O 2 in He, was led over the catalyst at a flow rate of 100 mL/min (STP), which was equivalent to a gas hourly space velocity (GHSV) of 60,000 mL g −1 h −1 . In spite of this relatively high space velocity, the use of a heavily diluted feed and the dilution of the catalyst with inert material minimized overheating of the catalyst bed [2,33]. The activities were measured as a function of temperature from 400 to 800 • C, with a heating rate of 10 • C/min and waiting 60 min for each 50 • C step and back to 600 • C with the same rates.…”

“…It allows 10-15% reduction in the energy requirement as compared to SRM. Additionally, the produced synthesis gas with H 2 /CO = 2 is suitable for methanol and Fisher-Tropsch syntheses [2]. In terms of cost and availability, nickel is the metal of choice for such a catalytic reaction.…”

“…Related to the experimental conditions of the reaction, two mechanisms for the partial oxidation of methane have been proposed, the direct partial oxidation route and the combustion-reforming reaction mechanism [2,14]. The direct mechanism, which is preferentially occurring at very short time (~10 −3 s), involves the dissociation of methane to carbon and hydrogen, with carbon reacting with oxygen, forming CO, and the hydrogen desorbing as H 2 .…”

The combustion mitigation of methane as a non-CO 2 greenhouse gas

“…There are several comprehensive review efforts in the literature summarising the state-of-the-art in the use of catalysts to enhance methane combustion [16,95,96], but none of them directly address their performance on the oxidation of ultra-lean methane mixtures. While it was found that Rd catalysts are better suited for methane partial oxidation [96], Pd and Pt catalysts are more appropriate for full oxidation because of the enhanced conversion of CH 4 to CO 2 on the catalyst surface [97]. Catalytic methane combustion is still an active area of research, to the authors' knowledge; no overall agreement is found about whether Pt or Pd catalysts perform better for methane catalytic conversion.…”