Preparation of shaped magnesium oxide/carbon catalysts using rice grains as an exotemplate and carbon precursor

•An in situ transformation technique was used to prepare biomorphic shaped MgO/C.•Nonporous rice particle was used as exotemplate and C precursor.•The biomorphic shaped MgO/C materials exhibit good catalytic performance.

Biomorphic magnesium oxide and magnesium oxide/carbon catalysts have been synthesized via an in situ transformation technique using rice grains as a template and carbon precursor. During preparation, MgO precursors are dispersed on the surface of rice grains with the aid of the rice-cooking process, and further transformed into solid bases upon calcination. Biomorphic MgO/carbon materials are formed when calcination is performed in a nitrogen atmosphere. These particles are spindle shaped catalysts with a circumference of several millimeters. Pyrolysis at higher temperature aids in the formation of porous structures, and the resulting MgO/carbon materials display high specific surface area (>260 m2/g) and more strongly basic sites. The presence of black carbon affects the catalytic behavior of MgO in the methylation of cyclopentadiene. These shaped MgO/carbon materials exhibit much higher catalytic performance than MgO at lower reaction temperatures.

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