Ively either can be esterified with methanol to create a black in Figure because the

Ively either can be esterified with methanol to create a black in Figure because the intermediate, which can then be competitively hemiacetal species oxidized to MMA as the preferred alkyl ester item or over-esterified with methanol to an acetal species as an undesired either oxidized to MMA asnanoparticles were item or over-esterified withthat the Au nanoparticles had been dispersed the preferred alkyl ester not observed, indicating methanol to an acetal species as an byproduct. undesired byproduct. having a compact size distribution and that bulky nanoparticles have been not developed.3.two. Impact of Help Crystallinities in CeO2 g(OH)2 Supporting Au Nanoparticles The crystallinities of CeO2 g(OH)2 for supporting Au nanoparticles might be controlled by changing the calcination temperature. From the controlled Ce:Mg ratios, we selected the sample with Ce:Mg = 37:63 as the 1 displaying the optimized catalytic performance (Figure two). Depending on the calcination temperature, the crystallinities in the CeO2 g(OH)two supports changed, as evidenced by the XRD patterns shown in Figure 3A. The XRD reflections progressively sharpened as the calcination temperature was elevated from 450 to 1000 . When the calcination temperature was 450 , the crystallinity was significantly reduce, as evidenced by quite broad XRD reflections.Figure two. Reaction summaries showing the MACR conversion product selectivity obtained Figure 2. Reaction summaries showing the MACR conversion and and product selectivity obtained by by using Au/CeO2 g(OH) with unique Ce:Mg ratios calcined at 750 . The outcomes using Au/CeO2 g(OH)two 2with distinctive Ce:Mg ratios calcined at 750 C. The outcomes are also are also Cucurbitacin D Autophagy summarized in Table 1. 1. The reaction carried out at 80 C for 1 h. summarized in Table The reaction Phenol Red sodium salt Description waswas carried out at 80 for 1 h.Figure 3. (A) X-ray diffraction patterns, (B) N2 adsorption/desorption isotherms with pore size distributions (inset), andThe series of Au metal nanoparticles supported on CeO2 g(OH)2 was investigated as the catalyst for the DOE reaction of MACR with methanol (Scheme 1). Figure 2 presents the reaction final results and shows the MACR conversion and solution selectivity according to the composition ratio of Ce and Mg within the catalyst support; the results are alsoNanomaterials 2021, 11,six ofNanomaterials 2021, 11,selectivity. When the ratio of Ce:Mg was between 80:20 and 37:63 in the synthesis gel, MACR conversion above 65 was achieved having a high MMA selectivity of close to 100 (Figure two).six ofWhen Mg(OH)2 was introduced towards the catalyst help, the Au-supporting CeO2 Mg(OH)2 catalysts made MMA as the preferred product. Because the amount of Mg(OH)2 in the CeO2 g(OH)two support increases, a pseudo-volcano distribution is observed for the MACR conversion (black dots in Figure two). When the ratio of Ce:Mg was in between 80:20 and 37:63 within the synthesis gel, higher MACR conversion values 67.43.9 had been obtained, along with the MMA selectivity was close to 100 . When the quantity of Mg precursor within the synthesis gel improved beyond 80 (Ce:Mg = 20:80), the MACR conversion dropped under 50 , and also the MMA selectivity also gradually decreased. When pure Mg(OH)two was applied as the assistance for Au nanoparticles inside the absence of CeO2 (Ce:Mg = 0:one hundred), the MACR conversion was Scheme 1. DOE reaction of MACR with methanol beneath aerobic circumstances by using oxygen as the oxidant. MACR can 40.3 , and also the MMA selectivity was correspondingly reduced to 72.5 . The volcano be esterified with methanol to create a hem.