Comparative study on hydrogen-assisted “one-step” methane conversion over Pd–Co/SiO2 and Pt–Co/NaY catalysts

Direct conversion of methane under nonoxidative conditions

“…Recently, they reported that the two-step process could be simplified into a one-step process with a C 2+ hydrocarbons production higher than that obtained in the two-step process over PtCo/NaY bimetallic catalyst. These results could be obtained if the CH 4 was pulsed with H 2 /He mixture at 523 K [23,24].…”

The influence of CO adsorption on the surface composition of cobalt/palladium alloys

“…[2][3][4] The doping of Co catalysts with metals such as Pd has resulted in improved performance in the conversion of methane to hydrocarbons [5] and CO hydrogenation. [6] A number of catalytic investigations [5][6][7] and model studies on CoPd nanoparticles grown on a flat alumina film [8][9][10][11] have investigated the promoting effect of Pd and it is proposed that the role of Pd is to enhance the adsorption of H 2 to facilitate the reduction of cobalt oxide forming the more active metallic phase.…”

A platinum–cobalt-loaded NaY zeolite membrane for nonoxidative conversion of methane to higher hydrocarbons and hydrogen

“…The Pt-Co/NaY catalyst exhibited 100% conversion of the chemisorbed CH x (x % 2) [13] with C 2+ selectivity of 83.6% in the rehydrogenation step. The enhanced performance of the Pt-Co/NaY catalysts was attributed to the increased reducibility of Co ions in NaY and the synergistic effect of Pt-Co on the C-C bond formation during hydrogenation [12].…”

“…The principle of CH 4 conversion through the catalytic membrane is proposed to have three basic steps as illustrated in figure 1: (1) decomposition of CH 4 on the CH 4 feed side surface, (2) surface diffusion of chemisorbed CH x through the Pt-Co-loaded zeolite channels to the H 2 sweep side driven by the gradient of surface coverage, and (3) rehydrogenation of the CH x species to form C 2+ under H 2 sweep. A limited back diffusion of H 2 can maintain a low level of H 2 on the CH 4 feed side surface and inside the catalyst-loaded zeolite pores that suppresses deep dissociation of CH x into inactive carbonaceous species and benefits the C 2+ selectivity [13].…”