(581b) 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.

References:

(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.