화학공학소재연구정보센터
Catalysis Today, Vol.379, 50-61, 2021
PdCu nanoalloy supported on alumina: A stable and selective catalyst for the conversion of bioethanol to linear alpha-alcohols
PdCu/Al2O3 (Pd = 0.1 wt.%, Cu = 0.1 wt.%) catalyst and its monometallic analogues (Pd/Al2O3 and Cu/Al2O3) were prepared by combination of deposition-precipitation and impregnation methods. The structure of the catalysts was studied by means of XRD, TEM, EDS, TPD-NH3, and DRIFTS. In a standard run (275 White circleC, 5 h), Cu/ Al2O3 converts 11 % of ethanol to alpha-alcohols with 0.6 % selectivity, whereas Pd/Al2O3 converts 24 % of ethanol to alpha-alcohols with 70 % selectivity. The high performance of Pd/Al2O3 was attributed to the catalysis on the Pd degrees Al2O3 interfaces. After 3 sequential runs, the activity of Pd/Al2O3 decreases by 98 %. It was explained by blocking of Pd degrees sites in Pd/Al2O3 by CO molecules produced in side reactions. Modification of Pd/Al2O3 with Cu species results in the formation of PdCu/Al2O3 catalyst containing PdCu alloy particles with the size of 4 nm. This leads to an increased durability of bimetallic sample, because of suppressing CO sorption on Pd degrees sites in alloy particles. As a result, for the PdCu/Al2O3 catalyst, sustained and high conversion (41 %) accompanied by high selectivity to alpha-alcohols (91 %) was observed in 20 sequential runs.