Low Temperature and H2 Selective Catalysts for Ethanol Steam Reforming

Abstract

Supported Rh catalysts have been developed for selective H 2 production at low temperatures. Ethanol dehydration is favorable over either acidic or basic supports such as c-Al 2 O 3 and MgAl 2 O 4 , while ethanol dehydrogenation is more favorable over neutral supports. CeO 2 -ZrO 2 -supported Rh catalysts were found to be especially effective for hydrogen production. We focused on a support prepared by a co-precipitation method having composition Ce 0.8 Zr 0.2 O 2 . A 2%Rh/Ce 0.8 Zr 0.2 O 2 catalyst, prepared via impregnation without pre-calcination of support, exhibited the highest H 2 yield at 450°C among various supported Rh catalysts evaluated in this study. This may be due to both the strong interaction between Rh and Ce 0.8 Zr 0.2 O 2 and the high oxygen transfer rate favoring reforming of acetaldehyde instead of methane production.

Sustainable Hydrogen Production by Catalytic Bio-Ethanol Steam Reforming

“…This adversely affects overall system efficiency due to heat losses and increases the capital cost for necessary hardware. As a result, low temperature ethanol steam reforming is an attractive alternative (Roh et al, 2006a;Roh et al, 2006b;Ciambelli et al, 2009;Ciambelli et al, 2010a;Ciambelli et al, 2010b;Palma et al, 2011). This operating range could be useful to obtain a H 2 rich gas stream, also reducing the overall thermal duty.…”

Hydrogen production from simple alkanes and oxygenated hydrocarbons over ceria–zirconia supported catalysts: Review

“…Addition of 0.5% potassium ('PH') had a beneficial effect on catalyst stability, while higher potassium content (about 5%) lowered the catalytic activity. A Ce0.8Zr0.2O2 support was the best formulation as a result of higher OSC, and strong interaction between Rh and Ce0.8Zr0.2O2 had a positive effect on the performance of the catalyst reflected in an increased oxygen transfer efficiency [62]. The deactivation behavior of this formulation was studied by Platon et al [44].…”

Hydrogen Production by Glycerol Steam Reforming with Ru‐based Catalysts: A Study on Sn Doping

“…Acidic supports generally promote dehydration reactions leading to byproducts, alkenes and finally coke, that deactivate catalysts. [34][35][36][37] Keeping in mind this framework, an excessive presence of acidic tin (mixed) oxides deposited onto a support (originally basic) will promote glycerol decomposition leading to high amounts of CO, and finally the coke deposition responsible for the observed catalyst deactivation, at longer reaction times for Ru-Sn0.58, and even more evident for the Ru-Sn4.68 system. On the other hand, in catalysts with lower Sn content, Ru sites very active for hydrogen production are exposed, but the observed increase in CO selectivity needs further attention.…”