Recent studies in hydrogen and oxygen spillover and their impact on catalysis

Hydrogen effects on the electric conductivity of a Pt/Al2O3 catalyst

“…The high-temperature peak (near 330~ can be interpreted as a charge transfer effect induced by desorption of the spilled-over hydrogen species [12]. This statement is in agreement with the reported results [3,14], showing that the hydrogen spillover is a slow process at room temperature. The second G-TPD pattem (curve 3) is much better structured and evidences two overlapping peaks near 100~ and 200~ After 250~ the two shoulders are located at 270 and 330~ The low temperature peak demonstrates that the catalyst is not completely reduced after one pretreatment run, the peak located at around 170~ corresponds to a reversible chemisorbed hydrogen on platinum, while the higher temperature shoulders can be associated with the desorption of interface and spilled over hydrogen species.…”

“…Special attention has been paid to investigating the complex role played by hydrogen in Pt/Al203-catalyzed reforming reactions, where the hydrogen is not only a reactant and/or a reaction product, but also modifies the catalyst surface and makes the support active [1][2][3].…”

Challenges in hydrogen adsorptions: from physisorption to chemisorption

“…Once the H concentration on the catalyst surface is high enough and the chemical potential of H on the catalyst is larger than that on the adsorbent surface, H diffusive flow from catalyst to adsorbent or hydrogen spillover would occur [56]. Such a mechanism has been observed for more than several decades on the study of H surface diffusion on solid substrates/receptors [57]. However, obviously there is no solid substrate/receptor which could meet the qualifications for hydrogen storage.…”

In situ catalyst activity control in a novel membrane reactor—Reaction driven wireless electrochemical promotion of catalysis

“…Spillover is defined as the migration of species from one solid phase where it is easily adsorbed and dissociated onto another solid phase in contact with the first one, where it does not directly adsorb (Teichner, 1990). While spillover is the migration from the catalyst to the support, reverse-or back-spillover refers to the migration from the support to the catalyst.…”