Enhancing the Reaction of CO2 and H2O Using Catalysts within a Nonthermal Plasma

The direct conversion of emitted and captured carbon dioxide into usable fuels remains a significant challenge and is a key element in the transition to net zero. Herein, we examine the reaction of CO2 and H2O over Ni- and Cu-based catalysts combined with nonthermal plasma (NTP) technology. The catalysis under NTP conditions enabled significantly higher CO2 conversion and product yield, which was almost six times higher than that of the plasma-only system. A maximum H2 concentration of ∼2500 ppm was achieved for the Cu/ZSM5 catalyst at 17% CO2 conversion. Comprehensive catalyst characterization together with the reaction performances reveals that Cu in a reduced state promotes both the CO2 and H2O conversion leading to H2 formation. In situ diffuse reflectance infrared spectroscopy (DRIFTS) coupled with mass spectrometry (MS) analysis of the gas phase products confirms that CO is the major active species to drive the water gas shift reaction to form H2 in addition to the direct CO2 and H2O interaction. It also explains how the different metal support interactions influence the CO adsorption and its interaction with water. Among the catalysts studied, ZSM5-supported Cu catalysts were found to be the most effective in facilitating the CO2 and H2O reaction to produce H2.

将排放与捕获的二氧化碳直接转化为可用燃料仍是一项重大挑战，同时也是实现净零排放转型的关键一环。本文研究了镍基、铜基催化剂结合非热等离子体（nonthermal plasma, NTP）技术下的二氧化碳与水反应体系。非热等离子体条件下的催化反应可显著提升二氧化碳转化率与产物产率，其性能几乎是纯等离子体体系的六倍。当二氧化碳转化率达17%时，Cu/ZSM5催化剂实现了约2500 ppm的最高氢气浓度。全面的催化剂表征结合反应性能测试结果表明，还原态铜可同时促进二氧化碳与水的转化，进而生成氢气。结合气相产物质谱（mass spectrometry, MS）分析的原位漫反射红外光谱（diffuse reflectance infrared spectroscopy, DRIFTS）证实，除二氧化碳与水的直接相互作用外，一氧化碳是驱动水煤气变换反应生成氢气的主要活性物种。该研究还阐明了不同金属-载体相互作用如何影响一氧化碳吸附及其与水的相互作用。在所研究的各类催化剂中，ZSM5负载型铜催化剂在促进二氧化碳与水反应生成氢气方面效果最优。