Ultrasound‐assisted Cinnamaldehyde Hydrogenation to Cinnamyl Alcohol at Atmospheric Pressure over Ru‐B Amorphous Catalyst

Abstract

The ultrafine Ru-B amorphous alloy catalyst was prepared by chemical reduction with KBH 4 . During liquid phase hydrogenation of cinnamaldehyde at atmospheric pressure, the Ru-B catalyst prepared exhibited excellent selectivity to cinnamyl alcohol. When the hydrogenation was performed with ultrasonic irradiation, the reaction rate could be greatly enhanced while the selectivity to cinnamyl alcohol remained almost unchanged. The hydrogenation rate was increased with the increase of either the ultrasonic frequency or the irradiation time. According to various characterizations, such as XRD, XPS, TEM, BET and ICP, the effect of ultrasonic irradiation on the structural and electronic characteristics of Ru-B catalyst was studied briefly. Meanwhile, the promotion effect of ultrasonication on the catalytic performance was also discussed based on the selective hydrogenation of cinnamaldehyde to cinnamyl alcohol.

Ultrasound-assisted sequentially precipitated nickel-silica catalysts and its application in the partial hydrogenation of edible oil

“…Furthermore, a decrease in binding energy also indicated a lowered extent of metal-support interaction between the Ni phase and Si phase [2] , [74] . In this case, a shift to lower binding energies due to ultrasound has also been reported by other researchers [75] , which led to a change in electron density that may affect the bonding of chemical intermediates to the active sites, thus ultimately affecting the reaction pathways during hydrogenation [76] , [77] , [78] . Furthermore, this indication of weakening in metal-support interactions is also corroborated with the TPR studies demonstrated earlier, noting the shift in main reduction peaks to lower temperatures in sonicated samples.…”

Synthesis and catalysis of chemically reduced metal–metalloid amorphous alloys

“…[102][103][104][105][106][107] Generally, the particle size can be controlled by adjusting the ultrasonication power [96][97][98] or time. 95,96 The effect of ultrasonication on the particle size is very pronounced for the Ru-B nanoparticles. 98 The conventional Ru-B nanoparticles displayed irregular, broadly distributed particles from 15-50 nm.…”

“…Selectivity manipulation is generally achieved by activating the carbonyl group and/or suppressing the adsorption of the conjugated olefinic bond or the phenyl ring. 211 Ni-, 81,82,86,128 Co-, 41,80,90,96,124,[212][213][214] and Ru-based amorphous alloy catalysts 95,215,216 have been investigated in chemoselective hydrogenation of unsaturated aldehydes or ketones. In the hydrogenation of furfural (FFR) to furfuryl alcohol (FFA), Mo, Ce, and Fe are effective promoters for Ni-B or Co-B.…”

“…To remove the disadvantage of conventional chemical reduction methods, various preparative strategies to uniform amorphous alloy nanoparticles have been developed, including the microemulsion method, 53,90,91 polymer stabilization, [92][93][94] and sonochemical technique. [95][96][97][98][99] 3.1.1 Microemulsion method. Microemulsion solutions are transparent, isotropic liquid media with nanosized water (oil) droplets dispersed in a continuous oil (water) phase and stabilized by surfactant molecules at the water/oil interface.…”

Ultrasonically improved semi-hydrogenation of alkynes to (Z-)alkenes over novel lead-free Pd/Boehmite catalysts

“…US has been used to overcome this problem and is usually reported to greatly accelerate the catalytic hydrogenation of olefins [29,54], cinnamaldehyde [55,56], 3-buten-2-ol [57,58], while selectivity to target products is either unchanged or increased under mild RT and AHP conditions. This effect has been attributed to sonication's dispersion effect on the catalyst and the effect of cavitation on the hydrogenation process.…”