Unraveling the activity of iron carbide clusters embedded in silica for thermocatalytic conversion of methane

Abstract

Isolated Fe-sites on silica substrate have recently been reported for direct and non-oxidative conversionof gaseous methane with high selectivity. The activated catalyst was proposed to be FeC2 clusterembedded in silica....

Role and dynamics of transition metal carbides in methane coupling

“…Transition metal carbides 1 are ubiquitous in catalysis today, particularly in the context of C-H activation. [2][3][4][5][6][7][8]28 While molybdenum and tungsten are prominent metals in state-ofthe-art catalysts for oxidative and non-oxidative coupling of methane, 9,10 MoO x /ZSM-5 has become the gold standard for methane coupling to aromatics. 9,11 For this system a characteristic induction period along with particle agglomeration is observed which is rationalized by a transformation of the molybdenum oxide to the corresponding oxycarbide or carbide species which is presumed to resemble the active species in methane coupling.…”

Role and Dynamics of Transition Metal Carbides in Methane Coupling

“…1 In particular, the Pt-like behavior of Mo and W carbides 2,3 has led to a popularization of metal carbides in catalysis, ranging from electrochemically-driven reactions 4 to thermal methane coupling. 5,6,7 Herein, we show the dynamics of Mo and W carbides and the active participation of carbidic carbon in the formation of C2 products during methane coupling. A detailed mechanistic study reveals that the catalyst performance of these metal carbides can be traced back to its carbon diffusivity and exchange capability upon interaction with gas phase carbon (methane).…”

Role of magnetization on catalytic pathways of non-oxidative methane activation on neutral iron carbide clusters

“…In addition, iron carbide clusters embedded in silica were instrumental in the direct nonoxidative conversion of methane without coke formation. 19,[25][26][27][28] It is, thus, desirable to examine the potential of neutral iron carbide clusters for methane activation, a crucial component of methane conversion. Theoretical studies of methane activation on neutral iron carbide clusters are currently lacking and can contribute to a better understanding of the chemistry between iron carbide clusters and methane.…”