(23f) Niobium Doped Molybdenum Disulfide Catalyst for CO2 Reduction Reaction

Authors: 
Abbasi, P., University of Illinois at Chicago
Asadi, M., University of Illinois at Chicago
Salehi-Khojin, A., University of Illinois at Chicago
Sayahpour, B., University of Illinois at Chicago
The world population consumes an average of 15 trillion watts of power, 85% of which comes from burning fossil resources including petroleum, natural gas, coal, and wood.1 Despite their low cost and high quality, the use of fossil fuels is unavoidably coupled to the release of many compounds such as carbon dioxide (CO2) that may adversely affect the environment such as acidifying oceans and climate change.2,3 Thus, controlling CO2 emission is essential using either renewable energy sources or remediation techniques. Among various remediation techniques, electrochemical reduction of CO2 is known as the best approach since it not only reduces the amount of existing CO2 in the atmosphere but also recycle the inert CO2 molecule into energy-rich products (e.g., syngas). Layered transition metal dichalcogenides (TMDCs) have recently shown a significant potential to use as the catalyst for a wide range of electrochemical energy conversion and storage systems such as hydrogen evolution and CO2 reduction4,5. However, it has been always a challenge to tailor the electronic structure of TMDCs to achieve highly promoted catalysts.

In this report, we have discovered a superior catalytic performance of Niobium (Nb) doped vertically aligned MoS2 (VA-MoS2) as an energy efficient and highly active catalyst for syngas production. Our results indicate that with only 5% Nb concentration at the edge atom structures, MoS2 exhibits more than two orders of magnitude higher activity than Ag nanoparticles and one order of magnitude higher than pristine MoS2 at low overpotentials (-0.2 V vs RHE).6 Additionally, the product characterization results reveal that this promoted catalyst is selective for syngas (CO and H2) formation at the potential range of -0.164 V to -0.764 V vs RHE. The effect of doping on the structure of pristine MoS2 was studied by synthesis and testing different concentrations of dopant for the CO2 reduction reaction. Different characterization methods such as scanning transmission electron microscopy (STEM), X-ray photoelectron spectroscopy (XPS), electron energy loss spectra (EELS), energy-dispersive X-ray spectroscopy (EDX) and in-situ differential electrochemical mass spectrometry (DEMS) were applied to fully elucidate the effect of dopant on the electronic structure of MoS2 and its catalytic activity and selectivity.

 

References:

(1) Davis, S. J.; Caldeira, K.; Matthews, H. D. Future CO2 Emissions and Climate Change from Existing Energy Infrastructure. Science. 2010, 329, 1330â??1333.

(2) Haszeldine, R. S. Carbon Capture and Storage: How Green Can Black Be? Science. 2009, 325, 1647â??1652.

(3) Lastoskie, C. Caging Carbon Dioxide. Science. 2010, 330, 595â??596.

(4) Behranginia, A.; Asadi, M.; Liu, C.; Yasaei, P.; Kumar, B.; Phillips, P.; Foroozan, T.; Waranius, J. C.; Kim, K.; Abiade, J.; et al. Highly Efficient Hydrogen Evolution Reaction Using Crystalline Layered Three-Dimensional Molybdenum Disulfides Grown on Graphene Film. Chem. Mater. 2016, 28, 549â??555.

(5) Asadi, M.; Kumar, B.; Liu, C.; Phillips, P.; Yasaei, P.; Behranginia, A.; Zapol, P.; Klie, R. F.; Curtiss, L. A.; Salehi-Khojin, A. Cathode Based on Molybdenum Disulfide Nanoflakes for Lithiumâ??Oxygen Batteries. ACS Nano, 2016, 10 (2), pp 2167â??2175.

(6) Asadi, M.; Kumar, B.; Behranginia, A.; Rosen, B. a; Baskin, A.; Repnin, N.; Pisasale, D.; Phillips, P.; Zhu, W.; Haasch, R.; et al. Robust Carbon Dioxide Reduction on Molybdenum Disulphide Edges. Nat. Com. 2014, 5, 4470.