Pt-Al-TUD-1: A bifunctional catalyst for liquid phase hydrogenation of MIBK

Liquid Phase Hydrogenation of MIBK over M/CsPW (M = Ag, Ru, Pt, and Pd)

“…Other metals, Pt, Ru, Ag, exhibited lower activity for this reaction, with 8%, 5% and 2% conversion, respectively. From these results and previous results reported by our group and others [10][11][12][13], we confirm that this is a truly bi-functional (metal/acid) system where both metallic and acidic active sites are essentially required to obtain the alkane product in liquid and gas phase. For the optimization of reaction conditions, the reaction was studied under different temperatures and pressures, the results are presented in Figure 5.…”

“…The results obtained clearly show that two different active sites are necessary to perform the conversion of MIBK to 2-MP. The use of only acidic catalyst CsPW could not activate the reaction (Figure 5), which was expected based on the initial results reported earlier [13]. The sequence of the reaction steps can be summarized as the following; (a) reduction of MIBK to 4-methylpentane-2-ol by metallic active sites and hydrogen gas, (b) dehydration of 4-methylpentane-2-ol to the alkenes intermediate by the acidic active sites, and finally (c) hydrogenation of the intermediate alkenes to form the desired product 2-methylpentane.…”

“…The sequence of the reaction steps can be summarized as the following; (a) reduction of MIBK to 4-methylpentane-2-ol by metallic active sites and hydrogen gas, (b) dehydration of 4-methylpentane-2-ol to the alkenes intermediate by the acidic active sites, and finally (c) hydrogenation of the intermediate alkenes to form the desired product 2-methylpentane. Pd-CsPW possessing strong acidity with purely Brønsted sites has shown similar activity to Pt-Al-TUD-1 [13] which has moderate acidity and both Brønsted and Lewis sites. In a kinetic study conducted by Alharbi et al [12], the first step in MIBK hydrogenation process to MP is the rate-determining step, which is the hydrogenation of the C=O group to the alcohol group.…”

“…Also, the hydrogenation of alkene intermediate over the metal site is fast [12]. It is interesting to mentioned that Pt incorporated TUD-1 catalyst [13], i.e., metallic nanoparticles only without acidic sites, was able to hydrogenate MIBK to 4-methylpentane-2-ol, and 0% of 2-MP was obtained, as an indication for the needs of the two different active sites to perform the conversion to the desired product 2-MP.…”

“…It is worth mentioning that the direct conversion of the liquid MIBK without using any solvents would be more favorable as it increases the economic value and reduces the environmental impact of the overall industrial process. Recently, our group reported the conversion of MIBK over the bi-functional catalyst Pt-Al-TUD-1 for the first time under liquid-phase, solvent-free conditions [13], and the results obtained were promising and motivated the team to investigate further the catalytic conversion of MIBK over different bi-functional catalysts, with more acidic support aiming to increase the overall conversion of MIBK.…”