SiO₂-supported Ni phosphide catalysts are highly active toward the non-oxidative coupling of methane (NOCM) reaction, and their catalytic activity is strongly dependent on their Ni:P ratio. We analyzed Ni phosphide catalysts using X-ray absorption fine structure (XAFS) to elucidate the structure-catalytic activity relationship. Because only Ni₂P was available as a reference material, we calculated the theoretical XAFS based on the reference crystal structures using the FEFF program and compared them with the experimental spectra of Ni phosphide catalysts. We demonstrated that catalysts with Ni to P ratios of 1:1, 2:1, and 3:1 consisted mainly of the Ni₂P, Ni₁₂P₅, and Ni₃P, respectively. We found that Ni₂P exhibited the highest activity toward NOCM because of its optimum balance of C–H cleavage activity and coke formation. This analysis demonstrated that the theoretical XAFS simulation could be used to identify the structure of supported catalysts based on the crystal structure of reference compounds.

SiO ₂负载的磷化镍催化剂对甲烷的非氧化偶联（NOCM）反应具有高活性，其催化活性强烈依赖于它们的 Ni:P 比。我们使用 X 射线吸收精细结构 (XAFS) 分析了磷化镍催化剂，以阐明结构-催化活性关系。由于只有 Ni ₂ P 可用作参考材料，我们使用 FEFF 程序基于参考晶体结构计算了理论 XAFS，并将它们与 Ni 磷化物催化剂的实验光谱进行了比较。我们证明了 Ni 与 P 比例为 1:1、2:1 和 3:1 的催化剂主要由 Ni ₂ P、Ni ₁₂ P ₅和 Ni _{3 组成}P，分别。我们发现 Ni ₂ P 对 NOCM 表现出最高的活性，因为它在 C-H 裂解活性和焦炭形成之间达到了最佳平衡。该分析表明，理论 XAFS 模拟可用于基于参考化合物的晶体结构来识别负载型催化剂的结构。