本文从催化剂微结构和动力学角度，认识和理解碳纳米管和α-Al₂O₃负载Pd催化乙炔半加氢反应的载体效应。动力学分析、XPS、H₂-TPR、TPHD和原位XRD研究结果表明：与α-Al₂O₃相比，碳纳米管作为载体降低了催化剂Pd⁰ 3d的电子结合能且抑制了氢化钯物种的形成，从而显著提高了目标产物乙烯的收率。进一步结合XAS、HRTEM、C₂H₄-TPD和DFT计算，发现碳纳米管负载的催化剂中Pd纳米颗粒次表面存在碳原子，这种独特的局域环境能显著弱化目标产物乙烯的吸附，有利于乙炔半加氢反应的发生。这些研究结果预示着调变Pd催化剂的局域环境和电子性质是一种构筑乙炔半加氢Pd催化剂的有效策略。

In this study, the support effects on the Pd-catalyzed semi-hydrogenation of acetylene have been investigated from the structural and kinetic perspectives. According to the results of kinetic analysis and X-ray photoelectron spectroscopy, hydrogen temperature-programmed reduction, temperature-programmed hydride decomposition, and in situ X-ray diffraction measurements, using carbon nanotubes as support for Pd nanocatalysts with various sizes instead of a-Al₂O₃ decreases the Pd0 3d binding energy and suppresses the formation of undesirable palladium hydride species, thus increasing the ethylene yield. Furthermore, X-ray absorption spectroscopy, high-resolution transmission electron microscopy, and C₂H₄ temperature-programmed desorption studies combined with density-functional theory calculations reveal the existence of a unique Pd local environment, containing subsurface carbon atoms, that produces positive geometric effects on the acetylene conversion reaction. Therefore, tailoring the Pd local environment and electronic properties represents an effective strategy for the fabrication and design of highly active and selective Pd semi-hydrogenation catalysts.