The hydrogenation of levulinic acid (LA) to γ-valerolactone (GVL) under mild condition is a promising but challenging process. Herein, SiC supported Ru-Ir bimetallic catalyst exhibit enhanced catalytic activity for aqueous hydrogenation of LA into GVL under mild conditions. Comparing with monometallic Ir 3 /SiC and Ru 3 /SiC, the conversion of LA over bimetallic Ru 0.5 -Ir 2.5 /SiC catalyst increase from 51.2 % and 45.9% to 100% at 25 °C and 0.2 MPa of H 2 pressure. The enhanced catalytic activity of Ru 0.5 -Ir 2.5 /SiC catalyst originates from the electronic synergistic effect among Ru, Ir and SiC. Due to the electron transfer, electron-richened Ir nanoparticles show stronger ability for H 2 dissociation, and the SiC surface produces more active sites to accommodate hydrogen species that spill over from Ir and Ru. The adsorption and hydrogenation of LA molecules occur on the surface of SiC.
Kun Liu,Houkun Long,Guangyi Wang,Yongbin Sun,Chao Hou,Jian Dong,Xiaoqun Cao
The catalyst Cu3Pt1–Cu2O/SiC was facilely prepared via the in situ reaction of the corresponding compounds supported on SiC in the reaction stream. Cu3Pt1–Cu2O/SiC exhibits excellent catalytic activity for the oxidation of alcohols (conversion of benzyl alcohol and selectivity of benzyl aldehyde are 93% and 98% respectively). The reduction of active Cu2O to inactive Cu0 is the cause behind the deactivation of Cu/SiC. For Cu3Pt1–Cu2O-7/SiC, a Cu2O–Cu3Pt1 alloy formed under the reaction conditions plays an important role in the reaction. Active 5 nm Cu2O nanoparticles are stabilized by the inactive Cu3Pt1 alloy, which was confirmed by control experiments, characterization results and a three-step experiment.
Graphical [+] These authors contributed equally to this articleDurable CuO/ZnO/CeO 2 /ZrO 2 catalyst on SiC support for methanol steam reforming was prepared by the combination of inverse microemulsion method and precipitation method. The methanol conversion of the catalyst was still reached 98.8 % after 150 h, considerably higher than that of solution combustion method (70 %), without carbon deposition and pronounced sintering after the reaction. Durable CuO/ZnO/CeO 2 /ZrO 2 catalyst on SiC support for methanol steam reforming (MSR) was prepared by the combination of inverse microemulsion method and precipitation method which is termed as inverse microemulsion/precipitation method. The presence of Ce−O−Zr solid solution facilitated the production of oxygen vacancies and Ce 3+ species in the prepared CuO/ZnO/CeO 2 /ZrO 2 catalyst. Owing to the unique tiny reaction pool and the addition of precipitant for inverse microemulsion/precipitation method, the particle size of the prepared catalyst was principally between 2 and 6 nm, with an average size of 3.66 nm. Besides, the small particle size and the highly dispersed of Cu species boosted the reduction performance of the catalyst, enabling the reduction temperature to be only 201 °C. The methanol conversion of the reduced catalyst was still reached 98.8 % after 150 h, considerably higher than that of solution combustion method (70 %), without carbon deposition and pronounced sintering after MSR reaction.
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