Tuning catalytic properties in Ru-MnOx/Al2O3 catalysts by crystal engineering of MnOx for ethyl levulinate hydrodeoxygenation

Crystal phase engineering proves to be pivotal in shaping the catalytic activity of catalysts. This study thoroughly investigates the influence of MnOx crystal phases on the properties of Ru-MnOx/Al2O3 catalysts, particularly focusing on acidic and electronic properties. Electronic properties were scrutinized through H2-TPR, XPS, and EPR, revealing disparate Ru species reducibility. Acid properties, elucidated by NH3-TPD and Py-FTIR, exhibited variations in weak and strong acids. These distinctions manifest in diverse product distributions during the hydrodeoxygenation of ethyl levulinate, showing gamma Ru3.75Mn15Al as optimal for 1,4-pentanediol yield and alpha Ru3.75Mn15Al for 2-butanol. Additionally, recyclability tests of gamma Ru3.75Mn15Al and Ru3.75Mn15Al catalysts show sustained high activity and negligible metal leaching, underscoring their stable nature. This comprehensive exploration sheds light on the intricate interplay of catalyst components and their profound impact on yields of biomass-derived products. It advances the understanding of catalytic processes, contributing to the evolution of sustainable biomass refining.