XPS and in situ IR spectroscopic studies of CO/Rh/Al2O3 and CO/Rh/K–Al2O3 at high temperatures: probing the impact of the potassium functionalization of the support

摘要: Potassium-functionalised alumina (6 wt.% K–Al2O3) was obtained by calcination at 973 K of pure particles (Al2O3) impregnated with an aqueous solution K2CO3. Both Al2O3 and K–Al2O3 were, then, RhCl3·3H2O, dried 393 K, in situ reduced H2 atmosphere to obtain 1 Rh/Al2O3 Rh/K–Al2O3 catalysts, respectively. Impacts the potassium-functionalization on high-temperature behaviour Rh catalyst towards CO were examined (i) X-ray photoelectron spectroscopic analysis surface chemical composition, (ii) particle sizing content means transmission electron microscopy, (iii) in infrared spectroscopy adsorbed CO. Results showed suppress CO-induced oxidative degradation Rh0 metal into RhI, enrich electronic density sites, stabilize against CO-assisted elimination high temperatures. On other hand, presence potassium found not affect initially dispersity despite promoting effect decomposition.