Nano-gold supported on Fe2O3: A highly active catalyst for low temperature oxidative destruction of methane green house gas from exhaust/waste gases

Abstract A number of nano-gold catalysts were prepared by depositing gold on different metal oxides (viz. Fe 2 O 3 , Al 2 O 3 , Co 3 O 4 , MnO 2 , CeO 2 , MgO, Ga 2 O 3 and TiO 2 ), using the homogeneous deposition precipitation (HDP) technique. The catalysts were evaluated for their performance in the combustion of methane (1 mol% in air) at different temperatures (300–600 °C) for a GHSV of 51,000 h −1 . The supported nano-gold catalysts have been characterized for their gold loading (by ICP) and gold particle size (by TEM/HRTEM or XRD peak broadening). Among these nano-gold catalysts, the Au/Fe 2 O 3 (Au loading = 6.1% and Au particle size = 8.5 nm) showed excellent performance. For this catalyst, temperature required for half the methane combustion was 387 °C, which is lower than that required for Pd(1%)/Al 2 O 3 (400 °C) and Pt(1%)/Al 2 O 3 (500 °C) under identical conditions. A detailed investigation on the influence of space velocity (GHSV = 10,000–100,000 cm 3  g −1  h −1 ) at different temperatures (200–600 °C) on the oxidative destruction of methane over the Au/Fe 2 O 3 catalyst has also been carried out. The Au/Fe 2 O 3 catalyst prepared by the HDP method showed much higher methane combustion activity than that prepared by the conventional deposition precipitation (DP) method. The XPS analysis showed the presence of Au in the different oxidation states (Au 0 , Au 1+ and Au 3+ ) in the catalyst.

[1]  Toshio Hayashi,et al.  Selective Vapor-Phase Epoxidation of Propylene over Au/TiO2Catalysts in the Presence of Oxygen and Hydrogen , 1998 .

[2]  S. Järås,et al.  Catalytic Materials for High-Temperature Combustion , 1993 .

[3]  B. E. Nieuwenhuys,et al.  A comparative study of the oxidation of CO and CH4 over Au/MOx/Al2O3 catalysts , 2001 .

[4]  V. Choudhary,et al.  Low‐Temperature Complete Combustion of Methane over Mn‐, Co‐, and Fe‐Stabilized ZrO2 , 1996 .

[5]  Masatake Haruta,et al.  Gold catalysts prepared by coprecipitation for low-temperature oxidation of hydrogen and of carbon monoxide , 1989 .

[6]  J. Chaouki,et al.  Combustion of methane over La0.66Sr0.34Ni0.3Co0.7O3 and La0.4Sr0.6Fe0.4Co0.6O3 prepared by freeze-drying , 1994 .

[7]  V. Choudhary,et al.  Epoxidation of styrene by t-butyl hydroperoxide over gold supported on Yb2O3 and other rare earth oxides , 2004 .

[8]  P. Kooyman,et al.  Influence of the Preparation of Au/Al2O3 on CH4 Oxidation Activity , 2000 .

[9]  V. Choudhary,et al.  Epoxidation of styrene by anhydrous t-butyl hydroperoxide over reusable gold supported on MgO and other alkaline earth oxides , 2004 .

[10]  J. E. Smith,et al.  An investigation of the activity of coprecipitated gold catalysts for methane oxidation , 1994 .

[11]  V. Choudhary,et al.  Low temperature complete combustion of dilute methane over Mn-doped ZrO2 catalysts: factors influencing the reactivity of lattice oxygen and methane combustion activity of the catalyst , 2002 .

[12]  Naonobu Katada,et al.  COMPLETE OXIDATION OF METHANE ON SUPPORTED PALLADIUM CATALYST: SUPPORT EFFECT , 1996 .

[13]  C. Louis,et al.  Alternative Methods for the Preparation of Gold Nanoparticles Supported on TiO2 , 2002 .

[14]  Christopher J. Kiely,et al.  Methane oxidation using Au/MgO catalysts , 1998 .

[15]  J. Chaouki,et al.  Evaluation of some cobalt and nickel based perovskites prepared by freeze-drying as combustion catalysts , 1993 .

[16]  Y. Mizushima,et al.  Alumina aerogel for support of a methane combustion catalyst , 1992 .

[17]  T. R. Baldwin,et al.  Catalytic combustion of methane over supported palladium catalysts: I. Alumina supported catalysts , 1990 .

[18]  Ronald M. Heck,et al.  Environmental catalysis into the 21st century , 2000 .

[19]  M. Najbar,et al.  Low temperature oxidation of light hydrocarbons over silica supported noble metal catalysts , 1993 .

[20]  Michel Primet,et al.  Catalytic oxidation of methane over palladium supported on alumina: Influence of the oxygen-to-methane ratio , 1992 .