Aljohani Meshal, Daly Helen, Lan Lan, Mavridis Aristarchos, Lindley Matthew, Haigh Sarah J, D'Agostino Carmine, Fan Xiaolei, Hardacre Christopher
Department of Chemical Engineering, The University of Manchester, Oxford Road, Manchester, M13 9PL, UK.
The Center of Excellence for Advanced Materials and Manufacturing, King Abdulaziz City for Science and Technology, Riyadh, 11442, Saudi Arabia.
Chempluschem. 2024 Feb;89(2):e202300411. doi: 10.1002/cplu.202300411. Epub 2023 Oct 30.
Photoreforming of lignocellulose biomass is widely recognised as a challenging but key technology for producing value-added chemicals and renewable hydrogen (H ). In this study, H production from photoreforming of organosolv lignin in a neutral aqueous solution was studied over a 0.1 wt % Pt/TiO (P25) catalyst with ultraviolet A (UVA) light. The H production from the system employing the lignin (4.8 μmol g h ) was comparable to that using hydroxylated/methoxylated aromatic model compounds (i. e., guaiacol and phenol, 4.8-6.6 μmol g h ), being significantly lower than that from photoreforming of cellulose (62.8 μmol g h ). Photoreforming of phenol and reaction intermediates catechol, hydroquinone and benzoquinone were studied to probe the mechanism of phenol oxidation under anaerobic photoreforming conditions with strong adsorption and electron transfer reactions lowering H production from the intermediates relative to that from phenol. The issues associated with catalyst poisoning and low photoreforming activity of lignins demonstrated in this paper have been mitigated by implementing a process by which the catalyst was cycled through anaerobic and aerobic conditions. This strategy enabled the periodic regeneration of the photocatalyst resulting in a threefold enhancement in H production from the photoreforming of lignin.
木质纤维素生物质的光重整被广泛认为是一种具有挑战性但关键的技术，用于生产增值化学品和可再生氢气（H₂）。在本研究中，在0.1 wt%的Pt/TiO₂（P25）催化剂上，使用紫外A（UVA）光，研究了在中性水溶液中有机溶剂木质素光重整制氢。使用木质素的体系产氢量（约4.8 μmol g⁻¹ h⁻¹）与使用羟基化/甲氧基化芳香族模型化合物（即愈创木酚和苯酚，4.8 - 6.6 μmol g⁻¹ h⁻¹）的产氢量相当，显著低于纤维素光重整的产氢量（约62.8 μmol g⁻¹ h⁻¹）。研究了苯酚以及反应中间体邻苯二酚、对苯二酚和苯醌的光重整，以探究厌氧光重整条件下苯酚氧化的机理，强吸附和电子转移反应使中间体的产氢量相对于苯酚有所降低。本文中所证明的与催化剂中毒和木质素光重整活性低相关的问题，通过实施一种使催化剂在厌氧和好氧条件下循环的工艺得到了缓解。这种策略使光催化剂能够定期再生，从而使木质素光重整的产氢量提高了三倍。
