Liuye Mo

One-step hydrogenation–esterification of furfural and acetic acid over bifunctional Pd catalysts for bio-oil upgrading

This contribution focuses on one-step hydrogenation-esterification (OHE) of furfural and acetic acid, which are difficult to treat and typically present in crude bio-oil, as a model reaction for bio-oil upgrading. A bifunctional catalyst is needed for OHE reaction. Among tested bifunctional catalysts, the 5%Pd/Al(2)(SiO(3))(3) shows the best catalytic performance. Compared to the physical mixture of 5%Pd/C+Al(2)(SiO(3))(3), there is a synergistic effect between metal sites and acid sites over 5%Pd/Al(2)(SiO(3))(3) for the OHE reaction. A moderate reaction condition would be required to obtain high yields of alcohol and ester along with lower byproduct yields. In this work, the optimum selectivity to desired products (alcohol and ester) of 66.4% is obtained, where the conversion of furfural is 56.9%. Other components, typically present in bio-oils, have little effects on the OHE of FAL and HAc. This OHE method is a promising route for efficient upgrading of bio-oil.

Combination of CO2 reforming and partial oxidation of CH4 over Ni/Al2O3 catalysts using fluidized bed reactor

The effects of the Ni loading, total feed flow rate, prereduction temperature, reaction temperature and feed gas ratio for combination of CO2 reforming and partial oxidation of CH4 over Ni/Al2O3 were investigated using a fluidized bed reactor. Methane conversion to syngas was drastically enhanced using a fluidized bed reactor over Ni/Al2O3 catalyst calcined at high temperature. The fluidized bed and the fixed bed reactor were compared and a promoting mechanism of the fluidized bed reactor was proposed.

A Novel Catalyst Pt/CoAl2O4/Al2O3 for Combination CO2 Reforming and Partial Oxidation of CH4

Pt/CoAl2O4/Al2O3, Pt/CoOx/Al2O3, CoAl2O4/Al2O3 and CoOx/Al2O3 catalysts were studied for combination CO2 reforming and partial oxidation of CH4. The results indicate that Pt/CoAl2O4/Al2O3 is the most effective, and XRD results indicate that Pt species are well dispersed over the Pt/CoAl2O4/Al2O3. High dispersion is related to the presence of CoAl2O4, formed during calcining at high temperature before Pt addition. In the presence of Pt, CoAl2O4 in the catalyst could be reduced partially at 973 K. Based on these results, it appears that zerovalent platinum with high dispersion and zerovalent cobalt resulting from CoAl2O4 reduction are responsible for high activity in the Pt/CoAl2O4/Al2O3 catalyst.

Ni/SiO 2 catalyst prepared with nickel nitrate precursor for combination of CO 2 reforming and partial oxidation of methane: characterization and deactivation mechanism investigation

The performance of Ni/SiO2 catalyst in the process of combination of CO2 reforming and partial oxidation of methane to produce syngas was studied. The Ni/SiO2 catalysts were prepared by using incipient wetness impregnation method with nickel nitrate as a precursor and characterized by FT-IR, TG-DTA, UV-Raman, XRD, TEM, and H2-TPR. The metal nickel particles with the average size of 37.5 nm were highly dispersed over the catalyst, while the interaction between nickel particles and SiO2 support is relatively weak. The weak NiO-SiO2 interaction disappeared after repeating oxidation-reduction-oxidation in the fluidized bed reactor at 700°C, which resulted in the sintering of metal nickel particles. As a result, a rapid deactivation of the Ni/SiO2 catalysts was observed in 2.5 h reaction on stream.

One-Step Hydrogenation/Esterification Activity Enhancement Over Bifunctional Mesoporous Organic–Inorganic Hybrid Silicas

Bifunctional mesoporous organic–inorganic hybrid silica incorporating both platinum and organosulfonic acid groups were synthesized for use in simultaneously catalyzing the one-step hydrogenation/esterification (OHE) of acetic acid and acetaldehyde, which was considered as a model reaction for the upgrading of biomass-derived bio-oil. The work explored optimizing the synthesis procedure to generate a bifunctional catalyst with enhanced combined activity for the OHE reaction. The presence of Pt was found to enhance the acidic properties of the organosulfonic acid functionalized silica. The mechanism by which the Pt incorporation affected the acid sites was investigated by the using XPS, FT-IR, FT-Raman characterization. The XPS results indicated the presence of electron transfer between the Pt and –SO3H groups. The FT-IR and FT-Raman results, which were in agreement with XPS, demonstrated an electron density increase for S and a S–O bond energy increase, which was proposed to be the reason for the acidity enhancement due to the presence of Pt. Additionally, arenesulfonic acid groups were substituted for propylsulfonic acid groups and the resulting material had higher catalytic activity due to the increased acid strength. An optimal synthesis procedure was demonstrated in which the Pt was first impregnated on the mesoporous silica using reductive deposition. Then Pt was activated and the material further modified by grafting on arenesulfonic acid groups. The resulting catalyst was about four times more active than the original base case bifunctional material.