Hydrogen production from oxidative steam reforming of ethanol over rhodium catalysts supported on Ce–La solid solution

Abstract

, which is 150 K lower than that required for comparable performance with 1%Rh/ CeO 2 . La doping also enhanced the stability by accelerating CH 3 COCH 3 conversion and gave low CO selectivity due to the high water gas shift activity. X-ray diffraction and Raman spectroscopy characterizations indicate the formation of CeeLa solid solutions and oxygen vacancies. H 2 temperature-programmed reduction and thermo-gravimetric measurement results confirmed that the redox properties of Rh/CeO 2 were greatly enhanced by La doping, which accelerated ethanol conversion, promoted H 2 yield, and maintained good longeterm activity for the OSR reaction.

Improved ethanol steam reforming on Rh/Al2O3 catalysts doped with CeO2 or/and La2O3: Influence in reaction pathways including coke formation

“…The reaction products were followed using a quadrupole mass spectrometer (Hiden Model HPR-20) connected on line to the reactor through a heated capillary tube. The transient-MS signals at m/z = 2, 15,18,26,28,29,30,31,44 and 58 were continuously recorded for H 2 , CH 4 , H 2 O, C 2 H 4 , CO, C 2 H 4 O, C 2 H 6 , C 2 H 5 OH, CO 2 and C 3 H 6 O respectively. The intensity of each product was represented by the selected signal after subtracting the possible contributions of fragments from other compounds.…”

“…O (ads) + HCO (ads) HCOO (ads) (18) Changes in gas phase composition during TPD of ethanol were monitored by mass spectrometry. As can be observed in Fig.…”

“…The promoting effect of CeO 2 is attributed to: (i), its higher reducibility in the presence of noble metals (ii), the improvement of metal active particles dispersion and, (iii), prevention of sintering of metal particles. Additionally, this type of promoters enables the reversible addition and removal of oxygen which facilitates coke gasification [17][18][19][20][21]. In the case of La 2 O 3, the promoting effect has been attributed to the formation of lanthanum oxycarbonate species (La 2 O 2 CO 3 ) which reacts with surface carbon deposited during reaction, and hence preventing deactivation [4,22].…”

Improved stability of Ni/Al2O3 catalysts by effect of promoters (La2O3, CeO2) for ethanol steam-reforming reaction

“…Likewise, CeO 2 has also shown excellent results in catalyst stability as it favors the coke gasification and WGS reaction due to its capacity to store, release and transport oxygen. Additionally, CeO 2 improves the redox reversibility of metallic phase and has been observed that can prevent the loss of surface area of bare alumina and the sintering the metallic species during the thermal treatment [26][27][28].…”

The Effect of Precipitants on Ce-La Solid Solution Prepared from Mixed Rare Earth Chloride by a Co-Precipitation Method

“…Our previous work showed that the proper La/(Ce+La) molar ratio is 20~50 mol.% of Ce 1-x La x O y solid solution supported Rh catalysts for ethanol oxidative steam reforming reaction [31]. The similar phenomenon was also be found in water-gas shift and combustion of methane reaction [25,30].…”