Surface-Modified Carbon Nanotubes Catalyze Oxidative Dehydrogenation of n -Butane

• DOI: 10.1126/science.1161916
• Publication Date: 2008-10-02T21:14:26Z
• Authors: Jian Zhang; Xi Liu; Raoul Blume; Aihua Zhang; Robert Schlögl; Dang Sheng Su
• Keywords: 02 engineering and technology; 0210 nano-technology

Butenes and butadiene, which are useful intermediates for the synthesis of polymers and other compounds, are synthesized traditionally by oxidative dehydrogenation (ODH) of n -butane over complex metal oxides. Such catalysts require high O 2 /butane ratios to maintain the activity, which leads to unwanted product oxidation. We show that carbon nanotubes with modified surface functionality efficiently catalyze the oxidative dehydrogenation of n -butane to butenes, especially butadiene. For low O 2 /butane ratios, a high selectivity to alkenes was achieved for periods as long as 100 hours. This process is mildly catalyzed by ketonic C

O groups and occurs via a combination of parallel and sequential oxidation steps. A small amount of phosphorus greatly improved the selectivity by suppressing the combustion of hydrocarbons.