266752 Solution Combustion Synthesized Catalytic Materials for Oxidative Coupling of Methane
Oxidative Coupling of Methane (OCM) to C2 hydrocarbons (ethane and ethylene) is an attractive opportunity for valorization of natural gas (>95% methane)1. Solution combustion synthesis (SCS) is a novel one-step technique for the preparation of nanostructured complex metal oxides with tailored composition, phase, oxidation state, and surface areas 2-4. In this work, SCS was used successfully for synthesis of several promising OCM catalyst series with varying metal ratios and structures: (a) Strontium – Aluminum mixed oxides, (b) Sodium – Lanthanum oxides, (c) Strontium – Aluminum - Lanthanum mixed oxides, (d) Na2WO4 - Mn/SiO2. All these catalysts exhibit C2 yields among the highest in the literature, a superior C2 selectivity and a higher desired ethylene/ethane ratio.
The various catalyst series were optimized by varying the metal ratios, temperature, flowrates and feed CH4/O2 ratios. Among the four catalyst series tested, the Na2WO4-Mn/SiO2 series showed the best performance. Detailed characterization was conducted to understand the basis for catalyst performance.
(1) Kondratenko E.V., Baerns M., Handbook of Heterogeneous Catalysis, Viley-VCH Verlag 2008, 3010-3023.
(2) Deshpande, K.; Mukasyan, A.; Varma, A., Journal of the American Ceramic Society 2003, 86(7), 1149-1154.
(3) Deshpande, K.; Mukasyan, A.; Varma, A., Chemistry of Materials 2004, 16(24), 4896-4904.
(4) Erri, P.; Dinka, P.; Varma, A., Chemical Engineering Science 2006, 61 (16), 5328-5333.