Novel Co‐Mn‐O nanosheet catalyst for CO preferential oxidation toward hydrogen purification

Abstract

Co-Mn-O composite oxide nanosheet catalyst was successfully prepared using a facile urea-assisted one-step hydrothermal method in the absence of organic or organic templating reagent. Co-Mn-O nanosheet catalyst was optimized by varying hydrothermal process parameters such as molar ratio of Co-Mn to urea, hydrothermal temperature, and hydrothermal time. Various characterization techniques including scanning electron microscopy, X-ray diffraction, nitrogen adsorption, X-ray photoelectron spectroscopy, Raman spectroscopy, and H 2 temperature-programmed reduction were used to reveal the relationship between catalyst nature and catalytic performance in CO preferential oxidation (CO PROX) in excess H 2 . The developed Co-Mn-O nanosheet catalyst have demonstrated much superior catalytic performance to Co-Mn-O nanoparticle, particularly in the low temperature range, and 100% CO conversion over the developed Co-Mn-O nanosheet can be achieved in temperature range of 50 to 150 C at 10,000 mL g 21 h 21 of gas hourly space velocity in the standard feed. Furthermore, the almost complete CO removal over Co-Mn-O nanosheet at 125 C of low temperature with 94.9% selectivity can be achieved even in the simulated reformed gas. The excellent catalytic performance is ascribed to nanosheet morphology, more surface Co 31 , smaller average crystallite size, higher reducibility, and strong Co-Mn interaction. Catalytic stability investigation indicates the developed nanostructured catalyst exhibits high catalytic stability for CO PROX reaction in simulated gas. The developed Co-Mn-O nanosheet catalyst can be a potential candidate for catalytic elimination of trace CO from H 2 -rich gas for Proton exchange membrane fuel cell applications. Reaction conditions: 100 mg catalyst, GHSV 5 15,000 mL h 21 g 21 , 1.0 vol % CO, 1.0 vol % O 2 , 50 vol % H 2 , Ar balance. [Color figure can be viewed in the online issue, which is available at wileyonlinelibrary.com.] 242 Figure 8. The CO conversion (a) and O 2 selectivity to CO 2 (b) over the Co-Mn-O-ns samples prepared with diverse n Co-Mn/Urea . Reaction conditions: GHSV 5 15,000 mL h 21 g 21 , 1.0 vol % CO, 1.0 vol % O 2 , 50 vol % H 2 , Ar balance. [Color figure can be viewed in the online issue, which is available at wileyonlinelibrary.com.]

CuO/CeO 2 based monoliths for CO preferential oxidation in H 2 -rich streams

“…If H 2 is addressed to PEM fuel cell CO content must be reduced to 10-50 ppm, and consequently a further step of preferential oxidation of CO (CO-PROX) is required [1][2][3].…”

More active Ir subnanometer clusters than single‐atoms for catalytic oxidation of CO at low temperature

“…Also, in industry, CO can pollute many catalysts for important processes such as the anode Pt-based catalyst for polymer electrolyte membrane fuel cells, the Fe-based catalyst for the synthesis of NH 3 and so on. 1,2 Thus the concentration of CO should be decreased to an acceptable level. Compared with the methods to eliminate CO by air purification equipment or by activated carbon, the catalytic oxidization of CO to CO 2 are more and more recognized and accepted.…”

High‐Performance Co‐MnOx Composite Oxide Catalyst Structured onto Al‐Fiber Felt for High‐Throughput O3 Decomposition

“…These two strong peaks differentiated from an overlapped peak between 550 and 750 cm À 1 show lower wavenumbers in comparison to the MnO x -Al, suggesting the existence of strong interaction between Co and Mn oxides. [49,50] Upon increase of Co/Mn molar ratio from 0.17 to 0.56, the Raman peaks of MnO x species become boarder and weaker, most likely due to the improvement of MnO 2 transformation into low-valent manganese species ( Figure 4B). No any characteristics peak of CoO x are identified in the Raman spectra of all Co-MnO x -Al samples even though Co 3 O 4 phase is detected by XRD in cases of Co/Mn molar ratio of � 0.36 ( Figure 4B).…”