大连理工大学李翔团队通过综合程序升温还原和红外光谱法理解过渡金属磷酸盐还原为过渡金属磷化物。 相关研究成果于2021年3月3日发表于国际顶尖学术期刊《德国应用化学》。

过渡金属磷酸盐前驱体的程序升温还原是制备过渡金属磷化物（一类新型多功能金属催化剂）最常用的方法，但还原过程尚不清楚。

该文介绍了一种程序升温还原红外光谱仪（TPR-IR）的构造，用于分析镍、钼和磷酸钨还原过程中的气体流动。低温（约200℃）下，气体流动中已出现PH3和Pn+物种，PH3参与了磷化物的形成。磷酸钼和磷酸钨还原过程中PH3和Pn+的排放量均小于磷酸镍。Ni2P显著加速了PH3和Pn+的形成。

该研究结果解释了制备Ni2P需要过量磷的原因，也说明了TPR-IR技术是了解催化剂制备复杂过程的有效方法。

附：英文原文

Title: Understanding the Reduction of Transition‐metal Phosphates to Transition‐metal Phosphides by Combining Temperature‐programmed Reduction and Infrared Spectroscopy

Author: Qiang Sheng, Xiang Li, Roel Prins, Chunjing Liu, Qinglan Hao, Shaozhang Chen

Issue&Volume: 2021-03-03

Abstract: Temperature‐programmed reduction of transition‐metal phosphate precursors is the most commonly used method for the preparation of transition‐metal phosphides (a new class of versatile metal catalysts), but the reduction processes are still not clear. Here we describe the construction of a temperature‐programmed reduction‐infrared spectroscopy apparatus (TPR‐IR) to analyze the gas flows during the reduction of nickel, molybdenum, and tungsten phosphates. PH  3  and P  n+  species already appeared in the gas flows at low temperature (ca. 200  o  C), and PH  3  was involved in the formation of phosphides. The emission of PH  3  and P  n+  during the reduction of the molybdenum and tungsten phosphates was smaller than that of the nickel phosphate. Ni  2  P drastically accelerated the formation of the PH  3  and P  n+  . These results explain why excess phosphorus is needed for the preparation of Ni  2  P, and also demonstrate that the TPR‐IR technique is an efficient method to understand the complex processes of catalyst preparation.

DOI: 10.1002/anie.202100767

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202100767