High efficiency Al modified mesoporous SBA-15 catalyst for biomass-derived γ-valerolactone decarboxylation to butene

A series of xwt%Al-SBA-15 catalysts prepared by modified wetness impregnation was investigated for γ-valerolactone (GVL) decarboxylation to butene. It was found that the impregnation of Al species not only remained the ordered mesoporous structure of parent SBA-15, but also created large amounts of Brønsted and Lewis acid sites on the surface of catalyst. The considerable amount of solid acid sites and the suitable Brønsted/Lewis acid ratio endowed 2.23 wt%Al-SBA-15 catalyst an excellent catalytic performance. Under the optimized conditions, the GVL conversion and butene yield can reach 99.8% and 96.6% at 320 °C, respectively. Mechanism studies indicated that the decarboxylation of γ-protonated PEA controlled speed of the whole reaction. Moreover, the catalytic activity of regenerated 2.23 wt%Al-SBA-15 catalyst was satisfactory after eight cycle tests, and the butene yield could still reach 92.2%.