In the substantial variation in oxygen storage capacity and lability among the three supports employed (Table 1). ItNanomaterials 2021, 11,13 ofis apparent from Figure 6a that, although all three catalysts exhibit practically the same methane consumption prices, the CO2 consumption rates differ appreciably based around the nature from the assistance. In specific, iridium supported on CZ and ACZ exhibits a a lot larger intrinsic activity compared to Ir/-Al2 O3 , with Ir/CZ getting general probably the most active, particularly at reduced temperatures. In addition, the CO2 consumption apparent Nitrocefin medchemexpress Activation energies (Ea ) are reduce for the CZ-containing catalysts with Ea decreasing from 91.three kJ/mol on Ir/-Al2 O3 to 88.five kJ/mol on Ir/ACZ and to 73.5 kJ/mol on Ir/CZ (Table 2). Regarding the CH4 consumption price, all catalysts exhibited comparable Ea Olesoxime References values of about 92.four kJ/mol (Figure 6a). This behavior suggests that a bifunctional reaction mechanism requires location, which is a lot more pronounced on supports with higher oxygen storage capacity (labile lattice oxygen). Specifically, surface oxygen vacancies, that are abundant on the ACZ- and CZ-supported catalysts, could activate CO2 by adsorption and disproportionation to CO O. Subsequently regenerated labile oxygen ions could then promote the oxidation of carbon deposited on the assistance and simultaneously boost the oxygen ion spillover onto the Ir particles, building an [O- , ] successful double layer on their surface. This benefits in alteration with the electronic state, properties and surface chemistry of Ir nanoparticles by metal-support interactions. The impact of your as-created double layer on the electronic state of noble metal particles has been lately revealed by state-of-the-art XPS measurements on Rh nanoparticle catalysts dispersed on -Al2 O3 – and CZ-containing supports related to these made use of in the present work [6]. It was shown that, beneath DRM situations, the Rh species existed primarily inside the metallic state (Rh0 ) plus the relative Rh0 content decreased with decreasing the OSC of your assistance, following the order Rh/CZ (Rh0 = one hundred ) Rh/ACZ (Rh0 = 72 ) Rh/-Al2 O3 (Rh0 = 55 ). It can be affordable to recommend that a qualitatively similar effect in the support’s OSC on the electronic state from the dispersed metal is also operable within the case of Ir nanoparticles, thereby favoring their DRM activity when dispersed on CZ-containing supports in comparison with -Al2 O3 . Moreover, the spillover oxygen species may also act as promoters of the DRM reaction prior to they react with CH4 -derived adsorbed carbonaceous species on Ir websites [83]. The CO-enriched syngas developed by Ir/ACZ and Ir/CZ catalysts (Figure 6b) is constant with this interpretation too as with temperature programmed oxidation (TPO) benefits performed more than made use of catalysts described under. The enhanced basicity of ceria-containing supports, which has been proposed to promote the reverse water gas shift reaction [1,two,6,7], might also clarify the larger CO content along with the lower H2 /CO molar ratio on the reformate, observed for the CZ-containing catalysts.Table 2. Support-induced effects on apparent activation energies and pre-exponential aspects of CO2 consumption price in the course of DRM more than Ir/-Al2 O3 , Ir/ACZ and Ir/CZ catalysts. Catalyst Ir/-Al2 O3 Ir/ACZ Ir/CZ Assistance t-OSC ( ol O2 /g) 0 110 557 rCO2 Apparent Activation Power (Ea ) (kJ/mol) 91.three 0.4 88.five 0.three 73.5 0.two Pre-Exponential Factor ( ro ) CO2 (mol CO2 / gIr ) 4146.four 1.7 3827.six 1.three 645.five 1.Nanomaterials 2021, 11, x FOR.