Abstract:

Safe hydrogen storage and efficient hydrogen production are critical challenges for the large-scale application of hydrogen energy. Utilizing methanol as a hydrogen storage medium and achieving mild continuous on-site hydrogen production through photo-driven methanol-water reforming is an effective approach for utilizing hydrogen energy. However, slow hole transfer kinetics and methanol dehydrogenation oxidation rate are bottlenecks that limit the performance of photocatalytic hydrogen production from methanol aqueous solution. Herein, based on the regulation of catalyst nanostructures, we constructed one-dimensional long diameter nanorod-like Zn_0.5Cd_0.5S (ZCS-LNR) photocatalyst to accelerate the photogenerated charge carrier separation and migration efficiency. By introducing NaOH alkaline medium, the rapid activation of OH^- and efficient dehydrogenation ability of ·OH are harnessed to facilitate surface hole transfer and enhance the rate of methanol oxidation dehydrogenation through the OH^-/·OH redox couple, thereby achieving high-performance hydrogen production from an alkaline methanol aqueous solution. Among them, the ZCS-LNR catalyst can obtain a hydrogen production rate of 54.33 mmol/(g·h) under the conditions of room temperature, 1.0 W/cm² light intensity, 4 mol/L NaOH and a CH₃OH/H₂O volume ratio of 1∶1. This study provides a novel feasible reaction pathway for achieving efficient photocatalytic hydrogen production from methanol aqueous solution.

Key words: catalyst, hydrogen production, nanostructure, methanol-water reforming, hole transfer

摘要：

安全储氢和高效制氢是实现氢能大规模应用的关键。利用甲醇作为储氢介质，并通过光能驱动甲醇-水重整制氢以实现温和连续现场制氢是促进氢能利用的一种有效途径。然而，缓慢的空穴转移和甲醇脱氢氧化速率成为限制光催化甲醇-水溶液制氢性能的瓶颈。基于催化剂纳米结构调控，通过构筑长径纳米棒Zn_0.5Cd_0.5S（ZCS-LNR）加快光生载流子分离和迁移速率，并通过引入NaOH碱性介质，利用OH^-的快速活化和·OH的高效脱氢能力，以OH^-/·OH氧化还原对加快催化剂表面空穴转移和甲醇氧化脱氢速率，实现了高性能的碱性甲醇-水溶液制氢过程。其中ZCS-LNR催化剂在室温、1.0 W/cm²光强、4 mol/L NaOH以及CH₃OH∶H₂O体积比为1∶1的条件下可获得54.33 mmol/（g·h）的产氢速率。为实现光催化甲醇-水溶液制氢过程提供了一种高效可行的新路径。

关键词: 催化剂, 制氢, 纳米结构, 甲醇-水重整, 空穴转移