Methane oxidation with O 2 over Cu catalysts supported on different zeolites. a) CH 4 conversion, b) yield of HCHO, c) yield of CO and d) yield of H 2 .

Contexts in source publication

Context 1

... Cr and Cu on SAPO showed higher catalytic activity for the oxidation of methane with O 2 , compared to the other 3d transition metal catalysts, as shown in Fig. 1(a). Although the catalytic activity of Cu/SAPO was similar to that of Cr/SAPO, the selectivity to HCHO over the former catalysts was significantly higher than that over the latter ones (Fig. S2 †). As the reaction temperature increased in the reaction over the Cu/SAPO catalyst, the selectivity to HCHO decreased, and that to CO increased instead, suggesting that HCHO was converted into CO over the Cu/ SAPO catalyst. It should be noted that the HCHO yield in the reaction over the Cu/SAPO catalyst was extremely higher than those ...

Context 2

... the formation of H 2 was confirmed during the reaction over the Cu/SAPO catalyst, although a substantial amount of gaseous O 2 remained in the reactants due to low O 2 conversion ( Table 1). The selectivity to H 2 was relatively high (28%) in the reaction over the Cu/SAPO catalyst at 773 K, and it did not decrease with the reaction temperature (Fig. S2d †). In contrast, in the case of the reaction over the Pd and Rh catalysts, H 2 and CO were only observed once nearly all gaseous O 2 was consumed ( Table 1). The reaction behavior over the Pd and Rh catalysts aligns with that over previously reported conventional catalysts active for the production of synthesis gas such as supported Ni ...

Context 3

... 2. The Cu loading was adjusted to be 0.5 wt% for all the Cu catalysts in Table 2. XRD patterns for these Cu catalysts are shown in Fig. S4. † Only diffraction lines due to the corresponding zeolites were observed in the XRD patterns for these catalysts, suggesting the presence of highly dispersed Cu species for all the Cu catalysts in Table 2 Fig. 2. Cu/SAPO and Cu/MOR which had higher activity for methane oxidation tended to show Table 2. In the XRD patterns for both catalysts, very weak peaks due to CuO were observed at 2θ = 35 and 39 degrees in addition to broad peaks due to the supports as shown in Fig. S6. † Cu species in these catalysts are present as small crystallites of ...