Nitrite reduction over Pd supported CNFs: Metal particle size effect on selectivity

Abstract

Pd catalysts supported on carbon-nano-fibres (CNFs) were synthesized via Pd colloids stabilized with polyvinyl-alcohol (PVA). Pd catalysts with narrow particle sizes distributions and mean Pd sizes between 2.6 and 30nm were immobilized on CNFs. Characterization with COchemisorption and transmission electron microscopy (TEM) revealed that a significant part of the Pd surface is blocked by the polymer layer on the Pd particles. The prepared catalysts were tested for nitrite reduction in water, resulting in formation of nitrogen and ammonia. Turn over frequencies were found to be independent of Pd particle size while selectivity to ammonia clearly decreased with increasing Pd particle size.

The selective hydrogenation of furfural over supported palladium nanoparticle catalysts prepared by sol-immobilisation: effect of catalyst support and reaction conditions

“…The reaction effluent was analysed by GC (Agilent 7890B) fixed with a CP-Wax 52 However, it has been reported previously that the presence of a stabiliser can significantly reduce the quantity of CO that can adsorb to the surface of catalysts prepared by the solimmobilisation method. 41 As such, in this study, the initial rate measurements were estimated by dividing the moles of substrate converted by the mass of metal in the reaction per unit time (h) after 30 minutes.…”

Bimetallic activated carbon supported catalysts for the hydrogen reduction of bromate in water

“…It has been observed that the addition of Cu to supported Pd catalysts reduces the availability of high coordination sites for reaction [28]. The low coordination sites, which become more predominant on the Pd surface with the addition of Cu, are known to have higher activity in hydrogenation reactions [29,30]. This behavior has been observed in the reduction of nitrates over Pd-Cu bimetallic catalysts, where the selectivity to the desired product (nitrogen) is hurt due to over hydrogenation [31].…”

Hydrogen production from formic acid decomposition in the liquid phase using Pd nanoparticles supported on CNFs with different surface properties

“…activated carbon, [23][24][25] zeolites, 26 macroreticular resins, 15 amines 16 and MOFs. 3,17,18 Carbon nanobers (CNFs) and carbon nanotubes (CNTs) have also been successfully used as supports for the synthesis of supported metal nanoparticles for a wide range of important catalytic applications such as alcohol oxidation, 27,28 nitrite reduction, 29 oxygen reduction reactions, 30,31 and hydrogen generation. 32,33 When compared with other supports, CNFs present advantages such as the possibility to tailor the microstructures of CNFs by selecting growth techniques, the control of the surface chemistry by surface modication and the facile recovery of the metal by burning off the support.…”