Alloys alkane hydrogenolysis

Furthermore, alkane hydrogenolysis, an undesired side reaction, is often encountered over pure platinum particles. It is known that hydrogenolysis is a demanding reaction requiring at least two adjacent platinum atoms. Therefore, alloying the noble metal by an inactive metal such as copper appeared as an appropriate solution to this problem. In addition, because alloying did not mo dify the size of the bimetallic particles, it increased the total number of those particles and, therefore, the overall number of isolated siuface platinum atoms. 

Whereas the hydrogenolysis of hexane and other alkanes (60, 62, 100, 101) can be observed only at temperatures slightly above the temperatures closing the miscibility gap in Ni-Cu alloys, reaction (II) occurs at substantially lower temperature, where separated phases (if present) are thermodynamically stable. 

An Alloying Effect The Hydrogenolysis of C-C Bonds in Alkanes over Ru Bimetallic Catalysts... 

Some aspects of the particle size, alloying effect, and metal-support interaction in nano-sized supported metal particles are presented for the oxidation of ethylene, the hydrogenolysis of alkanes, and the hydrogenations of unsaturated hydrocarbons and a,j8-unsaturated aldehydes. The influence of these phenomena is highlighted on the... 

AN ALLOYING EFFECT THE HYDROGENOLYSIS OF C-C BONDS IN ALKANES OVER Ru BIMETALLIC CATALYSTS... 

In the case of PtSn alloy systems, obtained by reaction of SnBu on Pt/Si02, dehydrogenation of alkanes (e.g., isobutane) becomes the major pathway (vs. hydrogenolysis) and up to 98% selectivity is achieved with catalysts... 

Similar mechanisms are postulated for commercial alkene/arene, carbonyl and nitrile hydrogenations on metal surfaces in particular, individual metal atoms are involved. In contrast hydrogenolysis, the cleavage of C—C or C—O (N, S, etc.) bonds, appears to need two or more adjacent sites and can sometimes be reduced by alloying the main component (addition of copper to nickel, for example). The stability of supported metal (especially platinum) catalysts permits their use at high temperatures, to promote hydrogen transfers between alkanes, alkenes and arenes or dehydrogenation processes. 

---