Copper-based nanocatalysts for 2-butanol dehydrogenation: Screening and optimization of preparation parameters by response surface methodology

Abstract

Two types of copper-based dehydrogenation nanocatalysts (Cu/ZnO/Al 2 O 3 and Cu/SiO 2 ) were prepared from various precursors by impregnation (IM), sol-gel (SG) and co precipitation (COPRE) methods. The structures of samples were characterized by N 2 adsorption-desorption, XRD, XRF, TPR, N 2 O-Titration, FT-IR, FE-SEM and TEM techniques. The catalytic performance tests in vapor-phase dehydrogenation of 2-butanol to methyl ethyl ketone (MEK) were carried out in a fixed-bed reactor at a temperature of 260 o C under atmospheric pressure and LHSV of 4 mL/(h·g cat). The experimental results indicated that (i) the copper oxide over the COPRE nanocatalyst was reduced at a lower temperature (222 o C) in comparison with the CuO reduced on the SG and IM samples (243 and 327 o C, respectively). Also, the percentage of reduction of CuO species on COPRE catalyst was the highest (98.8%) in comparison with the two other samples, (ii) the COPRE nanocatalyst exhibited the highest activity for the dehydrogenation of 2-butanol to MEK, and (iii) co-precipitation method was selected as an optimum method for preparation of nanocatalyst. The central composite experimental design method was applied for investigation of the effects of four critical preparation factors on the MEK selectivity of Cu/ZnO/Al 2 O 3 nanocatalyst. The results showed that Cu/Zn molar ratio and precipitation pH are the most effective factors on the response and the optimum conditions for synthesis of Cu/ZnO/Al 2 O 3 nanocatalyst with maximum selectivity of MEK were T (pre) =67.5 o C, T (aging) =68.8 o C, pH (pre) =7.27 and Cu/Zn molar ratio=1.38. The performance of the prepared nanocatalyst at the optimum conditions was comparable to the commercially available nanocatalyst.

Ketone Hydrogenation by Using ZnO−Cu(OH)Cl/MCM‐41 with a Splash of Water: An Environmentally Benign Approach

“…From previous reports, it deduced that individually ZnO and CuO have various properties such as high electron mobility, high catalytic activity, high chemical and thermal stability and non-toxicity, easy availability in nature as well as biocompatibility, [7,8,9] while a hybrid Copper-Zinc oxide catalyst possess application in steam forming, [10,11] methanol synthesis, [12,13,14] methanol reforming for fuel cell, [15] anodic material in lithium-ion batteries [16] and CO 2 fixation. [17] So, we have amalgamated them together and synthesized a catalyst with zinc and copper supported on mesoporous silica MCM-41.…”

Insights into the reactivity of zero-valent-copper-containing materials as reducing agents of 2,4,6-trichlorophenol in a recirculating packed-column system: Degradation mechanism and toxicity evaluation

“…Three replicates of the central point (10 mg L −1 TCP and 16.4 g ZVCow) were used for statistical validation, together with four star points (2.9 mg L −1 TCP and 16.4 g ZVCow, 10 mg L −1 TCP and 30.6 g ZVCow, 10 mg L −1 TCP and 2.2 g ZVCow, 17.1 mg L −1 TCP and 16.4 g ZVCow), see Table 3. The values of ZVCow dosage and TCP concentration that promoted the highest TCP degradation after 150 min were optimized following a response surface methodology (Geravand et al, 2015). Multiple regression analysis based on the least-squares method was performed using STATISTICA 7.0 software, in order to obtain the quadratic response surface models (Eq.…”

“…The model adequacy was evaluated using the Fisher test (Geravand et al, 2015). The ANOVA gives the regression and the lack-of-fit F-values (Table 4).…”