Alumina-Supported Spinel NiAl₂O₄ as a Catalyst for Re-forming Pyrolysis Gas

A spinel structure for NiAl₂O₄ in nickel-based alumina has a significant impact on catalytic performance. To illustrate the relationship between the textural properties of spinel and catalytic performance, four nickel-based alumina catalysts using co-precipitation with different calcination temperatures were prepared and evaluated for the re-forming of simulated pyrolysis gas (CH₄ + CO₂) and then applied to the re-forming of gaseous products from rice husks pyrolysis. The results indicated that the spinel structure could improve the catalytic performance. Various characterization methods combined with mechanism analysis were applied to illustrate the contribution of surface properties and structure parameters of the spinel catalysts on catalytic performance. The influence of spinel structure in catalysts on the textural properties, the specific form of surface nickel species, and the anticoking ability of the catalysts have been established. Finally, the relationship between the spinel structure of the catalysts and the catalytic re-forming performance has been thoroughly explained.