Influence of acid-base sites on ZnO–ZnCr2O4 catalyst during dehydrocyclization of aqueous glycerol and ethylenediamine for the synthesis of 2-methylpyrazine: Kinetic and mechanism studies

Isobutanol Synthesis from Syngas over Zn‐Cr Catalyst: Effect of Zn/Cr Element Ratio

“…The XPS spectra are shown in Figure 6‐ and Figure 6‐. The location of Zn 2+ (around 1022.2 eV and 1045.2 eV) and Cr 3+ (around 576.3 eV and 586.1 eV) ions implied that Cr and Zn ions over catalysts surface were Zn‐Cr spinel or ZnO phase . All spectra of catalysts also have a Cr 6+ peak at around 578.2 eV in Figure 6‐, suggesting that catalysts with different Zn/Cr element ratios have been over‐oxidized.…”

The role of non-stoichiometric spinel for iso-butanol formation from biomass syngas over Zn–Cr based catalysts

“…Features caused by the presence of Zn and Cr elements were all quite prominent. 22,26 In Fig. 6a, the binding energy value of Zn in ZnCra catalyst was located at an average of 1021.9 eV, while the binding energy value of Zn in ZnCr-b and ZnCr-c catalyst located at around 1022.1 and 1022.4 eV, respectively.…”

“…The binding energy value of Cr in ZnCr-c catalyst which is located at around 577.6 eV is also slightly larger than that of ZnCr-a and ZnCr-b catalysts which is located at around 576.7 and 577.1 eV, respectively. 22,26 The spectra of all catalysts contained a typical Cr 6+ peak at 578.1 eV, indicating that each of catalysts had partly been over-oxidized. 27 The difference of XPS peak intensities may be the result from the different amount of samples for each measurement.…”

Facile synthesis of CuMAl (M = Cr, Mn, Zn, and Co) with highly dispersed Cu and tailorable surface acidity for efficient 2-methylpyrazine synthesis

“…7 Thermal decomposition of layered double hydroxides (LDHs) is an attractive approach to obtain uniformly distributed metal nanoparticles. [7][8][9][10][11] Venugopal et al prepared LDHs-derived Cu/Zn-Cr-O catalysts and used them in the synthesis of 2,6dimethylpyrazine. However, the low surface area (50 m 2 g À1 ) and the large CuO x crystalline size (5.8 nm) of the catalyst resulted in a poor glycerol conversion (9%) at 375 C. 9 The formation of the LDH precursor can be signicantly altered by changing the secondary metal element (M) in CuMAl catalysts, thereby potentially leading to higher metallic Cu dispersion.…”