No abstract

No abstract

Steam reforming of ethanol was examined over Co/SrTiO 3 with addition of another metal-Pt, Pd, Rh, Cr, Cu, or Fe-for promotion of the catalytic activity. Ethanol conversion and H 2 yield were improved greatly by adding Fe or Rh at 823 K. Although Rh addition promoted CH 4 formation, Fe addition enhanced steam reforming of ethanol selectively. A suitable amount of Fe loading was in the window of 0.33-1.3 mol%. A comparative study of the reaction over a catalyst supported on SiO 2 was conducted, but no additional effect of Fe was observed on the Co/SiO 2 catalyst. High activity of Fe/Co/SrTiO 3 catalyst came from interaction among Fe, Co, and SrTiO 3 .

Structures of platinum and chromium supported on zeolite beta were investigated by XAFS, XPS, UV–vis, NH3-TPD, XRD, CO chemisorption, and molecular dynamics simulation. Both platinum and chromium were uniformly dispersed in the micropore of zeolite beta. Loading of chromium helped platinum to disperse highly and stabilized in the micropore of beta. Major species of platinum on PtCr/beta after calcination at 773 K was Pt2+ forming a Pt–O bond. The Pt–O bond disappeared, and a Pt–Pt bond did not appear by reducing PtCr/beta in hydrogen, accompanying formation of Pt0. Chromium was loaded as chromate anion in the micropore of zeolite. Results of molecular dynamics simulation showed that Pt2+ associated with CrO4 2– in the micropore of zeolite beta was more stable than those in the absence of chromium species. We concluded that CrO4 2– electrostatically stabilizes Pt2+ and inhibits migration and aggregation of platinum.

No abstract