Enhancing the H2 yield from photoreforming of natural lignocellulose feedstock by two-stage thermo-alkaline hydrolysis pretreatment

Abstract

The efficiency of hydrogen production from solar water splitting can be substantially increased by adding natural lignocellulosic feedstock as a sacrificial agent in the process. However, the efficiency of the hydrogen yield from photoreforming (PR) natural lignocellulosic feedstock is still far from that of model compounds. In this paper, we report a new pathway for boosting H₂ yield by simply applying a commercial SrTiO₃ catalyst in PR processes following thermo-alkaline hydrolysis acidizing (TAH-A), thermo-alkaline hydrolysis reversed-phase (TAH-RP) filtration, and two-stage thermo-alkaline hydrolysis (TS-TAH) pretreatment. The efficiency of the hydrogen yield from PR natural lignocellulosic feedstock was significantly improved through all the pretreatments. The greatest enhancement was found for TS-TAH corn stover, where the hydrogen yield reached 4.7 μmol, which is 2.3 times higher than that of TAH-RP filtration. The advantage was attributed to the elimination of most of the lignin from the corn stover following the TS-TAH. This greatly restrained the light-absorbing effect of lignin from the lignin-TAH-PR system, and more light energy was applied to excite the catalyst for H₂ evolution. This featured finding potentially provides a feasible method for in-depth utilization of natural lignocellulosic feedstocks in PR hydrogen production technology.