光热协同甲醇水蒸气重整制氢实验和微观机理研究

Experimental and Microscopic Mechanism Investigation of Photo-Thermal Methanol Steam Reforming for Hydrogen Production

针对太阳能光热化学甲醇重整制氢中光热耦合效应及微观机理尚不清楚的问题,采用光热化学和热化学反应对比的研究方式,与微观实验相结合,研究了光热化学甲醇重整中光和热的耦合效应,探究了光和热在微观产物转化中的反应路径。研究结果表明:在较低温度下,光对氢气产率的提升具有促进作用,当其与热化学达到相同氢气产率时,光热化学反应温度降低,造成这种现象的原因是光促进了水的分解、吸附态HCOO*的生成以及碳酸盐的分解,其中水在反应中的作用通过不同水醇比的实验得到了进一步验证;随着温度的升高,固定辐照度下光的促进作用逐渐降低,这是因为光对碳酸盐物质分解的促进作用随温度升高而减弱。研究阐明了光和热的耦合效应,分析了对应的微观机理,为理解光热协同机理提供了理论基础。

To address the limited understanding of the photo-thermal coupling effects and microscopic mechanisms involved in solar-driven photothermochemical methanol steam reforming for hydrogen production,a comparative study that compares the performance of photothermochemical reactions with thermochemical reactions is conducted,with the microscopic experiments complemented.This study aims to examine the synergistic effects of light and heat in photothermochemical methanol steam reforming and elucidate the reaction pathways of light and heat involved in the microscopic conversion of the reactants.The research findings reveal that,at relatively low temperatures,light has a positive influence on enhancing hydrogen yield.Compared to thermochemical reactions that achieve the same hydrogen yield,photo-thermochemical reactions operate at lower temperatures.The reason for the experimental observation is attributed to the facilitation of water dissociation,the generation of HCOO*,and the decomposition of carbonate species facilitated by light.The importance of water in the reaction is confirmed through experiments involving varying water-to-methanol ratios.Furthermore,as the temperature increases,the promoting effect of light diminishes under a fixed light intensity,which is primarily attributed to the light’s diminishing influence on the decomposition of carbonate species with increasing temperature.The study provides a clear understanding of synergistic effects of light and heat,and analyzes the corresponding microscopic mechanisms,thereby establishing a theoretical basis for understanding the photo-thermal synergistic mechanisms.