The Influence of Crystal Face in Catalysis

Adaptive machine and its thermodynamic costs

“…In certain enzymes and ion channels the functional part (performing the catalysis) couples to the conformational part that in its turn back-reacts on the functional part [13,14]. Structure-function interaction exists also in inhomogeneous catalysis [15]. It modifies the catalyst's structure and changes the catalytic current.…”

Ethylene dissociation on flat and stepped Ni(111): A combined STM and DFT study

“…Gwathmey et al made extensive studies on the influence of the crystal face on catalytic reactions [2], and Yates et al [3] used stepped single crystal surfaces to study the role of step edges in surface chemical reactions. Following the advent of scanning probe microscopy Zambelli et al [4] were able to provide direct evidence that the step edges are the active sites for the NO dissociation on Ru(0 0 0 1).…”

Catalysis by platinum single crystal surfaces: low pressure hydrocarbon reactions and the effects of introducing strongly bound oxygen at the surface

“…3.8, the maximum turnover numbers for benzene production from cyclohexarie are plotted as a function of oxygen coverage for both increasing oxygen coverage (the crystal was exposed to oxygen at 8QQOC until the desired coverage was reached) and decreasi oxygen coverage (the crystal was heated at lOQQOC and/or ion sputtered after each experiment to produce a lower oxygen coverage, In each case for decreasing oxygen coverage, a hydrocarbon experiment was run before the crystal was heated to lOOOOC and/or ion sputtered to lower the oxygen coverage. Thus, these results do not rule out " the possibility that the previous reaction itself is responsible for altering the surface 9 and hence the subsequent reactivity, and not the difference in treatment to obtain a given oxygen coverage. This could easily be checked by oxygen exposu~e at 8QQOC to reach a given oxygen coverage, followed immediately by flashing to lOOOOC to remove oxygen before running the hydrocarbon reaction.…”

“…low levels of hydrogenolysis reactivity of neo-pentane to iso-butane and of isobutane to propane were detected. The influence of low concentrations of strongly bound oxygen on the isomerization reactions was not studied 9 but would make an interesting investigation. and the various poles referred to these coordinates.…”