Schmuecker Samantha M, Leonard Brian M
Department of Chemistry, University of Wyoming, Laramie, Wyoming 82071, United States.
Inorg Chem. 2015 Apr 20;54(8):3889-95. doi: 10.1021/acs.inorgchem.5b00059. Epub 2015 Mar 30.
Nanostructured metal carbides are of particular interest because of their potential as high surface area, low-cost catalysts. By taking advantage of a salt-flux synthesis method, multiple carbide compounds were synthesized at low temperatures providing a pathway to nanosized materials. To better understand the reaction mechanism, vanadium carbide (V8C7) synthesis was monitored by quenching samples at 100 °C intervals and analyzed by multiple spectroscopic methods. The reaction was determined to occur through the formation of metal halide and acetylide carbide intermediates, which were repeatedly observed by X-ray diffraction and further supported by IR and Raman spectroscopies. Control experiments were also employed to further verify this mechanism of formation by using different salt compositions and a solid-state metathesis reaction. The reaction mechanism was also verified by applying these techniques to other metal carbide systems, which produced similar intermediate compounds.
纳米结构金属碳化物因其作为高表面积、低成本催化剂的潜力而备受关注。通过利用盐熔剂合成方法，在低温下合成了多种碳化物化合物，为制备纳米材料提供了一条途径。为了更好地理解反应机理，通过每隔100℃淬冷样品来监测碳化钒（V8C7）的合成，并采用多种光谱方法进行分析。确定该反应是通过形成金属卤化物和乙炔碳化物中间体而发生的，通过X射线衍射反复观察到这些中间体，并得到红外光谱和拉曼光谱的进一步支持。还进行了对照实验，通过使用不同的盐组成和固态复分解反应来进一步验证这种形成机理。通过将这些技术应用于其他金属碳化物体系，也验证了该反应机理，这些体系产生了类似的中间化合物。
