471764 Selective Deposition of Ni on Mo2c That Has Been Supported on Al2O3: Enhanced Stability for Dry Reforming of Methane

Thursday, November 17, 2016: 9:42 AM
Franciscan C (Hilton San Francisco Union Square)
Jayson Keels1, Khalid Askar1, John R. Monnier1 and John R. Regalbuto2, (1)Chemical Engineering, University of South Carolina, Columbia, SC, (2)Department of Chemical Engineering, University of South Carolina, Columbia, SC

In recent years, there has been much greater incentive to reduce greenhouse gas (GHG) emissions, CH4 and CO2 being the most potent offenders [1]. Biogas, which contains both GHG’s, is a largely under-utilized and passively emitted resource that may be used for energy production; therefore utilizing biogas represents not only an environmental benefit, but also a significant economic opportunity. One way to utilize biogas and provide a distributable source of energy is to catalytically convert it into liquid fuels. This may be achieved by first (dry) reforming CH4 with CO2 to form CO and H, followed by liquid fuel production reaction such as Fischer-Tropsch or dimethyl ether (DME) synthesis. Although there are a few cases in which dry reforming of biogas has been scaled to demonstration-sized facilities [2], it has not attained full scale production. One of the main barriers is catalyst deactivation due to coking [3]. In this presentation, we address this issue by both choice of support and preparation method of Ni-based catalysts.

Oxide-supported Ni catalysts have been modified by others using Mo2C in appropriate amounts to improve stability and activity [4, 5]. The enhanced stability has been attributed to a redox cycle where Mo2C is oxidized by CO2 which is then followed by recarburization from the coke deposited on Ni to re-form Mo2C [4]. However, no efforts have been made to ensure intimate contact between Ni and Mo2C when both are supported on a metal oxide surface. We demonstrate that Ni may be selectively deposited on Mo2C aggregates that have been previously supported on Al2O3; the enhanced interaction between Ni and Mo2C improve stability and provide more efficient utilization of the catalyst. Electroless deposition (ED) is used to selectively deposit Ni on Mo2C by activation of a reducing agent on the Mo2C surface to reduce a Ni2+ precursor in solution. Strong electrostatic adsorption (SEA) of the Ni2+ precursor on the Al2O3 surface is prevented by adjusting the pH of the solution to maintain the Al2O3 surface in a positive state. Thus, it is critical to avoid SEA of Ni on Al2O3 and to deposit Ni only on Mo2C.

The resulting catalysts have been evaluated for dry reforming of methane; activities and stabilities are compared with catalysts prepared by conventional co-impregnation. XRD, TPR, and CO chemisorption have been used to determine bulk and surface compositions. The selectivity of Ni deposition on Mo2C has been confirmed by STEM images.


[1] Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990 – 2014, in: E.P. Agency (Ed.), 2016.

[2] A. Corradini, J. McCormick, Process and system for converting biogas to liquid fuels, in, Google Patents, 2012.

[3] C. Papadopoulou, H. Matralis, X. Verykios, Utilization of biogas as a renewable carbon source: dry reforming of methane, in: Catalysis for Alternative Energy Generation, Springer, 2012, pp. 57-127.

[4] S. Zhang, C. Shi, B. Chen, Y. Zhang, Y. Zhu, J. Qiu, C. Au, Catalytic role of β-Mo 2 C in DRM catalysts that contain Ni and Mo, Catalysis Today, 258 (2015) 676-683.

[5] W. Li, Z. Zhao, P. Ren, G. Wang, Effect of molybdenum carbide concentration on the Ni/ZrO 2 catalysts for steam-CO 2 bi-reforming of methane, RSC Advances, 5 (2015) 100865-100872.

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See more of this Session: Catalysis for C1 Chemistry IV: CH4 Conversion II
See more of this Group/Topical: Catalysis and Reaction Engineering Division