Activation of nitrogen by alkali metal promoted transition metal I. Ammonia synthesis over ruthenium promoted by alkali metal

Probing the Electronic Effect of Carbon Nanotubes in Catalysis: NH3 Synthesis with Ru Nanoparticles

“…[20] A higher electron density around metal centers facilitates N 2 dissociation because it is an electrophilic process. [21] The bond of the N 2 molecule is weakened by the incorporation of an electron into its antibonding orbital, which was evidenced by an increase of the work function. [21] This has led to the development of the second-generation ammonia synthesis catalysts based on Ru supported on activated carbon (AC) promoted by alkali metals or their oxides, for example, K, in which K acts as an electron donor.…”

“…[21] The bond of the N 2 molecule is weakened by the incorporation of an electron into its antibonding orbital, which was evidenced by an increase of the work function. [21] This has led to the development of the second-generation ammonia synthesis catalysts based on Ru supported on activated carbon (AC) promoted by alkali metals or their oxides, for example, K, in which K acts as an electron donor. [22,23] Thus, if a shift of electron density from the concave inner to the convex outer CNT wall indeed plays a role in the catalytic activity of CNT-supported catalysts, one can expect that ammonia synthesis over Ru dispersed on the exterior CNT surface will exhibit a higher activity than the inside Ru catalyst.…”

H2/D2 isotopic exchange: A tool to characterize complex hydrogen interaction with carbon-supported ruthenium catalysts

“…It is more active than the conventional FeK catalyst while the other group 8-10 metals are much less active [10]. Carbon-supported Ru catalysts promoted by basic oxides were patented by British Petroleum and Kellogg for this application and further studied by Aika et al [11], Kowalczyk et al [12] and Li et al [13]. High graphitization of the carbon is generally required [14].…”

The effects of alkali metal on structure of manganese oxide supported on SBA-15 for application in the toluene catalytic oxidation

“…Additionally the area of reduction peak declines to some extent, which may be due to the K blocking on the surface of manganese oxides. Fewer amounts of metal oxides can be reduced [30,31]. As we all know that the toluene adsorption on the surface of the catalyst is essential for the catalytic activity.…”