Hollow-Structural Ag/Co₃O₄ Nanocatalyst for CO Oxidation: Interfacial Synergistic Effect

Abstract

Porous hollow-structural Co3O4 micropolyhedra were prepared by direct pyrolysis of zeolitic imidazolate framework (ZIF)-67 crystals in air. The Co3O4 primary nanoparticles and pore diameters increase with increasing calcination temperatures. Compared with the single Co3O4-350 catalyst, CO oxidation activity is greatly enhanced over the interface Ag/Co3O4-350 catalyst (T 100 = 120 °C and 8.8 × 10–2 molCO nm–2 s–1), which can be attributed to the improvement in surface-active oxygen and their mobility at the interface between Ag and Co3O4. The DRIFTS results proposed the CO oxidation reaction mechanism over the Ag/Co3O4 interface catalyst, and the formed Ag compound with surface oxygen species is more active for CO oxidation. The interface between Ag and Co3O4 facilitates both the oxygen activation and CO adsorption, hence lowering the reaction energy barrier and boosting the CO oxidation performance.

Rationally Designed Synthesis of Metal–Organic Framework-Derived Cobalt Oxide with Abundant Surface Active Sites for Efficient Catalytic Oxidation Performance

“…Five peaks appeared in all Co 3 O 4 catalysts. 190, 466, 510, 610, and 670 cm –1 was respectively assigned to F 2g (a), E g , F 2g (b), F 2g (c), and A 1g of spinel Co 3 O 4 , − respectively, and no impurities peaks of CoO or Co 2 O 3 could be observed in Figure a, which had been found in good compliance with the XRD results. However, the Raman peaks of Co 3 O 4 -160 shifted to a high wavenumber from Table S1, and especially the F 2g (b) and A 1g of Co 3 O 4 -160 had obviously red shift, which might be due to transmission of the phonons between agglomerated nanoparticles that produced larger Raman bands red-shift and line broadenings.…”

Interfacial effects in CuO/Co3O4 heterostructures enhance benzene catalytic oxidation performance

“…Further, it can also be seen that the lattice fringes of 0.231 and 0.252 nm correspond to the (211) and (002) planes of CuO, 56 and the lattice fringe of 0.244 nm is ascribed to the (311) plane of Co 3 O 4 . [57][58][59] Additionally, it can be obviously seen from Fig. S8 † that an interfacial edge exists between the different crystal planes (see yellow line), confirming the successful formation of CuO/Co 3 O 4 heterostructures.…”

Co-Supported CeO2Nanoparticles for CO Catalytic Oxidation: Effects of Different Synthesis Methods on Catalytic Performance

“…The structural properties of the catalysts are very important for the analysis of active sites in solid-gas reactions. Raman spectroscopy, as a structural characterization technique, has been widely used for this purpose in different catalytic reaction systems [32][33][34][35]. The Raman spectra of all CeO 2 and Co/CeO 2 catalysts are shown in Figure 8.…”