Influence of Ag metal dispersion on the thermal conversion of ethanol to butadiene over Ag-ZrO2/SiO2 catalysts

Ethanol-to-butadiene: the reaction and its catalysts

“…Recent computational and experimental techniques have highlighted the relationship between the dehydration-dehydrogenation activity of silver in Ag/ZrO 2 /SiO 2 catalysts and particle size. 245 Poorly dispersed metallic silver clusters were found to promote ethanol dehydration at the expense of acetaldehyde formation, resulting in lower butadiene selectivity. Rousseau et al concluded that high dispersion resulted in the partial charge of silver particles, which was identified as a crucial property for ethanol dehydrogenation.…”

Global optimization of chemical cluster structures: Methods, applications, and challenges

“…Example GMs of surface‐supported clusters obtained with (A) PGOPT and (B, C) NWPEsSe: (A) Pt 7 H 10 CH 3 @α‐Al 2 O 3 (0001) (PBE) [33], (B) Ag 55 @ZrO 2 /SiO 2 (PBE) [34], (C) Au 8 @oxygen‐defected rutile TiO 2 (110) [140]…”

“…Later, GO with first‐principles methods were carried out for the first time for gas phase atomic clusters (B3LYP) [28] and Ge 12 − 20 (PBE) [29] in 2005, for surface‐supported cluster Ag 1 − 4, 6, 8, 10 @MgO(100) (PBE) [30] in 2007, and for molecular cluster H(H 2 O) 1 − 4 (B3LYP) [31] in 2010. Since 2016, clusters in GO studies go beyond one‐ or two‐component systems and become larger and more complicated, like (CH 3 OSO 3 H) x (H 2 SO 4 ) y ((CH 3 ) 2 NH) z [32], Pt 7 H 10 CH 3 @α‐Al 2 O 3 (0001) [33], and Ag 55 @ZrO 2 /SiO 2 [34]. These exciting changes enable GO of clusters to be applied to more realistic chemical problems.…”

Recent Advances in Catalysts for the Conversion of Ethanol to Butadiene

“…A comparison of acidic ZrO 2 /SiO 2 and basic MgO/SiO 2 catalysts suggested that the strong basic sites in MgO/SiO 2 are more reactive in condensation reactions but suffer fast deactivation, in contrast to the acidic sites of both ZrO 2 /SiO 2 and MgO/SiO 2 . [81] Table 3 summarizes recent ETB acidic catalytic systems with SiO 2 [82][83][84][85][86][87][88][89][90][91][92][93] and ZrO 2 [94][95][96] as support. Some of these systems are used for the ethanol/acetaldehyde to butadiene conversion (step 2 of the two-step process).…”

“…The authors also investigated the impact of Ag dispersion on the properties of Ag/ZrO 2 /SiO 2 -SBA-16. [91] From the trend of the relative binding energy calculated by DFT, intermediates in the ETB reaction bind stronger on dispersed Ag in proximity to ZrO 2 than on Ag nanoparticles. The charge state of Ag was dependent on the dispersion, with well-dispersed interfacial Ag being cationic (Ag δ + ) while clustered Ag contain predominantly Ag 0 .…”