Stability of Ni/SiO2-ZrO2 catalysts towards steaming and coking in the dry reforming of methane with carbon dioxide

• Published in: Frontiers of chemical science and engineering Vol. 10; no. 2; pp. 281 - 293
• Main Authors: Stolze, Bettina, Titus, Juliane, Schunk, Stephan A., Milanov, Andrian, Schwab, Ekkehard, Gläser, Roger
• Format: Journal Article
• Language: English
• Published: Beijing Higher Education Press 01.06.2016
• Subjects: Chemistry; Chemistry and Materials Science; Industrial Chemistry/Chemical Engineering; Nanotechnology; Research Article; synthesis gas; Ni/SiO; coking; ZrO; dry reforming; steaming
• ISSN: 2095-0179; 2095-0187
• DOI: 10.1007/s11705-016-1568-0

Ni/SiO 2 -ZrO 2 catalysts with Ni loadings of 1 to 13 wt-% were prepared, characterized by elemental analysis, X-ray diffraction, N 2 sorption, temperature programmed oxidation, temperature programmed reduction, and tested for their activity and stability in the dry reforming of methane with carbon dioxide at 850 °C, gas hourly space velocity of 6000 and 1800 h –1 and atmospheric pressure. The SiO 2 -ZrO 2 support as obtained through a simple and efficient sol-gel synthesis is highly porous ( A BET = 90 m 2 ∙g –1 , d P = 4.4 nm) with a homogeneously distributed Si-content of 3 wt-%. No loss of Si or formation of monoclinic ZrO 2 , even after steaming at 850 °C for 160 h, was detectable. The catalyst with 5 wt-% Ni loading in its fully reduced state is stable over 15 h on-stream in the dry reforming reaction. If the catalyst was not fully reduced, a reduction during the early stages of dry reforming is accompanied by the deposition of up to 44 mg∙g –1 carbon as shown by experiments in a magnetic suspension balance. Rapid coking occurs for increased residence times and times-on-stream starting at 50 h. The Ni loading of 5 wt-% on SiO 2 -ZrO 2 was shown to provide an optimal balance between activity and coking tendency.