Phase-pure M1 MoVNbTeOx catalysts with tunable particle size for oxidative dehydrogenation of ethane

• Structure sensitivity of phase-pure M1 catalyst in ODHE was studied.
• Oxalic acid treatment is effective in morphology modification of M1 catalyst.
• Oxalic acid can promote the dispersion of starting needles of M1 catalyst.
• M1 catalyst with low aspect ratio may achieve excellent performance in ODHE.

This work presented a comprehensive study on structure sensitivity of phase-pure M1 catalyst in oxidative dehydrogenation of ethane (ODHE). We proposed an effective method to modulate the morphology of phase-pure M1 catalysts by oxalic acid treatment. The proposed approach significantly promoted the catalyst surface area by restraining the anisotropic growth of the basal (0 0 1) plane of the M1-phase in calcination and decreased the diameter of M1 needles. Experimental results showed that phase-pure M1 catalyst treated with 1.0 mmol/L oxalic acid solution exhibited remarkably promoted catalyst performance of 73% ethane conversion, 85% ethylene selectivity and 0.77 k C2H4/kgcat/h catalyst productivity at 400 °C. The serial catalyst tests also demonstrated the structure sensitivity of M1 phase in the ODHE reaction. Active sites were located on the lateral faces as well as the basal plane of the M1 needles, but different effects on the catalyst selectivity were observed. The phase-pure M1 catalyst with a lower aspect ratio was suggested to provide better ethylene selectivity in ODHE process.

Figure optionsDownload high-quality image (118 K)Download as PowerPoint slide