Ethane catalysts with metal cations

Basic supports such as calcined hydrotalcite-like materials are also employed for this purpose. Particularly, Sun et al. proposed Mg(Al)0 type hy-drotalcites to be the ideal catalysts. The Al cations present in the support stabilize the dispersed metal particles against sintering. Most of the reports in this direction suggest Sn as the best element for promotion. The size of Pt ensembles and the bond strength of chemisorbed hydrocarbons are modified by the addition of Sn. Thus, Pt-Sn combination performs better than Pt alone. Sn forms an alloy with platimun. The performance of the catalyst was foimd to be dependent on the composition of the Pt and Sn precursors and the catalyst preparation procedure. PtGa bimetallic nanoparticles were foimd to exhibit not only high activity and selectivity for ethane dehydrogenation, they also... 

It is interesting to note that the catalysts that show good selectivities at the higher temperatures generally do not contain easily reducible metal ions, such as V, Mo, or Sb. Many of the catalysts for the lower-temperatures operation, on the other hand, contain these reducible cations. In a study using a Li-Mg oxide, it was established that gas-phase ethyl radicals could be generated by reaction of ethane with the surface at about 600°C (17). These radicals could be trapped by matrix isolation and identified by electron spin resonance spectroscopy. 

The process of ethane oxidative chlorination imposes heavy demands on the catalysts. The conventional salt supported catalysts are composed of Cu, K, Ca, Mn, Co, Fe, Mg, and other metal chlorides containing various additives these salts are precipitated on alumina, zeolites, silica gel, and other supports. Catalytic systems that represent solid solutions of iron cations in the lattice of the a-A Oa and a-Ct203 phases doped with cations, such as K, Ba, Ce, and Ag are also known [7]. 

---