Surfactant-assisted hydrothermal synthesis of CuCr2O4 spinel catalyst and its application in CO oxidation process

Catalytic Oxidation of CO over Nanocrystalline La1–xCexNiO3 Perovskite‐Type Oxides

“…CO oxidation, water-gas shift (WGS) reaction, and CO preferential oxidation (PROX) are conventional technologies for the elimination of CO. Among the mentioned methods, catalytic oxidation is the most efficient technique for removing CO pollutants [3][4][5]. Catalytic CO oxidation is an attractive reaction with various industrial applications in CO 2 lasers, proton-exchange membrane (PEM) fuel cells, catalytic converters, etc.…”

Critical Review of Low-Temperature CO Oxidation and Hysteresis Phenomenon on Heterogeneous Catalysts

“…Results revealed essential mechanisms related to the formation and role of surface intermediates or inhibitors on the hysteresis behavior during CO oxidation with an increase in the hysteresis width as a result of self-inhibition, as shown in Figure 9 Koutoufaris et al used a model of the reactor behavior under transient conditions to investigate the effect of self-inhibition on the reaction propagation along the catalyst and its impact on hysteresis. Results revealed essential mechanisms related to the formation and role of surface intermediates or inhibitors on the hysteresis behavior during CO oxidation with an increase in the hysteresis width as a result of self-inhibition, as shown in Figure 9 Mobini et al reported inhibition effects on CuCr 2 O 4 spinel catalyst [142]. It was reported that high feed gas concentration influenced increase or decrease in temperature for CO conversion, again arising due to inhibition of the formation of hot spots in the catalyst bed, as shown in Figure 9b, thus leading to a momentary transition from a high conversion to low conversion of CO oxidation reaction over this catalyst [142].…”

“…Results revealed essential mechanisms related to the formation and role of surface intermediates or inhibitors on the hysteresis behavior during CO oxidation with an increase in the hysteresis width as a result of self-inhibition, as shown in Figure 9 Mobini et al reported inhibition effects on CuCr 2 O 4 spinel catalyst [142]. It was reported that high feed gas concentration influenced increase or decrease in temperature for CO conversion, again arising due to inhibition of the formation of hot spots in the catalyst bed, as shown in Figure 9b, thus leading to a momentary transition from a high conversion to low conversion of CO oxidation reaction over this catalyst [142].…”

“…Differently-shaped hysteresis curves such as, normal, inverse or rectangular shape, occur due to inhibiting species accumulation on the surface during temperature ramp-up which was reported for nanocrystalline CuCr 2 O 4 spinel catalysts in small-scale monolithic reactors, as shown in Figure 8. The small hysteresis is attributed to arise from high gas hourly space velocity (GHSV) of feed gas (60,000 mL/gh) which inhibits the formation of hot spots in the catalyst bed [142]. Koutoufaris et al used a model of the reactor behavior under transient conditions to investigate the effect of self-inhibition on the reaction propagation along the catalyst and its impact on hysteresis.…”

“…Increasing CO concentration in inlet gas causes a higher light-off temperature or ignition point, the hysteresis loop increases upon increasing the CO concentrations [52,56,74,77,87,126,142] Inlet Temperature Ignition and extinction shifted to higher temperatures with rapid increase in CO conversion [77,[128][129][130][131][132][133][134] Surface Contamination and Aging Increase in the hysteresis width due to the removal of contamination that blocks active sites [75,94,141] [55, 94,140] Rate of temperature ramp-up Increase in the temperature ramp-up result in shifting the ignition curve to higher temperatures [72,92] Inhibition parameters Different inhibiting species accumulation on catalyst surface can change the shape of hysteresis curves and increase the width of the hysteresis. [141,142].…”