Enhanced production of advanced renewable methanol-rich low-carbon alcohols via photocatalytic conversion of bio-oil

Bio-oil, deriving from sustainable biomass pyrolysis, presents significant promise as a source for the production of renewable low-carbon alcohols (C1–4 alcohols). Nevertheless, the intricate composition of bio-oil necessitates research into more eco-friendly and efficient conversion methodologies. In this context, an innovative and sustainable approach utilizing titanium dioxide (TiO2) as a catalyst has been successfully devised and implemented for photocatalytic conversion of bio-oil into methanol-enriched C1–4 alcohols under mild conditions. The TiO2 catalyst has undergone a comprehensive characterization, unveiling its remarkable crystallinity, mesoporous structure and outstanding optical absorption properties. Significantly, at ambient temperature, employing a TiO2 catalyst loading of 4 wt%, a reaction duration of 3 h and an ethanol-to-bio-oil molar ratio of 12:1, TiO2 demonstrated an exceptional selectivity of 66.24 % for C1–4 alcohols, with particular emphasis on a methanol selectivity of 38.96 %. This stands in stark contrast to the control groups, one of which lacks ethanol (resulting in selectivities of 2.18 % and 0.57 %, respectively), and the other lacks bio-oil (resulting in selectivities of 0 % and 0 %, respectively). Impressively, the overall alcohol selectivity reached a remarkable 68.79 %. Even after undergoing 5 reuse cycles, TiO2 continued to exhibit remarkable photocatalytic activity, maintaining methanol selectivity at 33.56 % and alcohol selectivity at 48.88 %. Additionally, the photocatalytic mechanism of bio-oil over TiO2 has been reasonably theorized. The results highlight the potential of TiO2 photocatalytic conversion of bio-oil to produce C1–4 alcohols rich in methanol.