CuO–CeO2/Al2O3 /FeCrAl monolithic catalysts prepared by sol-pyrolysis method for preferential oxidation of carbon monoxide

Abstract

This work describes a new technique, sol-pyrolysis method, for depositing CuO-CeO 2 on FeCrAl honeycomb supports. The monolithic catalysts prepared by the method presented good adhesion stability in ultrasonic and thermal shock tests. The principle of the deposition and the role of the support were studied and analyzed by SEM, XRD, TG-DTA, TPR and XPS techniques. The results showed that the active components adhered to the support via three stages. High surface energy of the crystal nuclei and the interaction between the active components and the support promoted adhesion stability. Moreover, the presence of the support influenced distribution and interaction of the active components, but had no obvious effect on catalytic performance. The CuOCeO 2 /Al 2 O 3 /FeCrAl monolithic catalysts were applied for the preferential oxidation of carbon monoxide in rich-hydrogen gases and revealed high activity and good selectivity under the presence of 15%CO 2 and 10%H 2 O.

Characterization of Active Sites/Entities and Redox/Catalytic Correlations in Copper-Ceria-Based Catalysts for Preferential Oxidation of CO in H2-Rich Streams

“…Other aspects of relevancy which have not been treated in detail in this contribution, are related to understanding the catalysts' deactivation mechanisms [76,77], particularly in the presence of CO 2 and H 2 O in the reactant mixture, which, as it occurs for nanogold systems, could limit the practical application of this type of catalyst. It must, however, be mentioned in this sense that monolithic forms of CO-PROX catalysts combining copper and ceria have displayed high performance for the process, even in the presence of important amounts of CO 2 and H 2 O in the reactant stream [78]. On the other hand, copper segregation and formation of metallic copper is shown to occur at T > ca.…”

Monoliths: A Review of the Basics, Preparation Methods and Their Relevance to Oxidation

“…The catalytic performance in this work, however, was assessed in the absence of H 2 O/CO 2 . In comparison, sol-pyrolysis of CuO-CeO 2 /Al 2 O 3 on a metallic monolith resulted in a good catalyst adherence, as well as a complete conversion of CO at 165 • C in the presence of H 2 O and CO 2 [294]. In addition, coating monoliths by solution-combustion synthesis has given materials with good catalytic performance for the PrOx reaction in the presence of H 2 O and CO 2 [295,296].…”

Macroporous Monolithic Pt/γ-Al2O3 and K–Pt/γ-Al2O3 Catalysts Used for Preferential Oxidation of CO

“…Over honeycomb monolith catalysts, to remove CO to 10 ppm via CO-PROX, the volume space velocity is 7,000 h -1 as showed in our previous work [32,33]. Over micro-channel reactor, the corresponding volume space velocity is 5,700 h -1 [34].…”

“…As for fuel cell oriented hydrogen production from hydrocarbons, miniaturisation is the key challenge [31]. For CO-PROX, a critical step for the hydrogen production, catalytic reactors such as honeycomb monolith (pore size in millimeter scale) and micro-reactor (channel width in several hundreds of microns) are widely studied for the miniaturisation [7,8,[32][33][34]. As stated above, the pore size of macro-porous monolith is several tens of microns, which is much smaller than the channel size of honeycomb monolith as well as the channel width of the micro-reactor.…”