Preparation of 27Ni6Zr4O143M(M=Mg, Ca, Sr, or Ba)O/70 zeolite Y catalysts and hydrogen-rich gas production by ethanol steam reforming

Abstract

In this study the effects of adding alkaline-earth (IIA) metal oxides to NiZr-loaded Zeolite Y catalysts were investigated on hydrogen rich production by ethanol steam reforming (ESR). Four kinds of alkaline-earth metal (Mg, Ca, Sr, or Ba) oxides of 3.0% by weight were loaded between the Ni6Zr 4O14 main catalytic species and the microporous Zeolite Y support. The characterizations of these catalysts were examined by XRD, TEM, H2-TPR, NH3-TPD, and XPS. Catalytic performances during ESR were found to depend on the basicity of the added alkaline-earth metal oxides and H2 production and ethanol conversion were maximized to 82% and 98% respectively in 27(Ni6Zr4O14)3MgO/70Zeolite Y catalyst at 600 °C. Many carbon deposits and carbon nano fibers were seen on the surface of 30Ni6Zr4O14/70Zeolite Y catalyst but lesser amounts were observed on alkaline-earth metal oxide-loaded 27(Ni6Zr4O14)3MO/70Zeolite Y catalysts in TEM photos after ESR. This study demonstrates that hydrogen yields from ESR are closely related to the acidities of catalysts and that alkaline-earth metal oxides reduce the acidities of 27(Ni6Zr4O 14)3MO/70Zeolite Y catalysts and promote hydrogen evolution by preventing progression to hydrocarbons. Copyright © 2005 KCSNET.