Reduction of Mn-MOF-5 Supported on Graphene As a Catalyst for Hydrolysis of Sodium Borohydride

Abstract

Metal borides are a class of catalyst that are known for their stability, high conductivity, and excellent catalytic capabilities.1 These materials may be an efficient catalyst for the hydrolysis of water to produce hydrogen gas. Hydrogen is the most abundant element in the universe and highly sought after for a clean burning, alternative fuel. Issues associate with storing compressed H2 gas has turned the focus to generating H2 from a hydrogen feedstock material (HFM). One such HFM known as sodium borohydride (NaBH4) contains 10.8% hydrogen by weight and reacts with water to produce H2 gas.2 Our group developed a novel method of synthesizing Manganese borides supported on graphene like materials (MnB@G) to catalyze the hydrolysis of sodium borohydride. Our group chose graphene as a support since previous work within this team showed that carbon allotrope supports can increase the catalytic capability of metal catalysts3,4. Our materials were prepared from the reduction of a manganese metal organic framework (MOF) supported on graphene oxide (MnMOF-5@GO) at room temperature (RT 295K). These metal borides were characterized using Fourier Transform Infrared Spectroscopy (FTIR), Powder X-Ray Diffraction (P-XRD), Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES), Transmission Electron Microscopy (TEM), Energy Dispersive X-Ray Spectroscopy (EDS), and Scanning Electron Microscopy (SEM, Figure 1) before they were tested for hydrogen generation at temperatures of 283K-303K. Our product showed an improved activation energy of 51 kJ mol-1 when compared to previous carbon allotrope supported catalysts.3,5 This work can be used to create new catalyst composites to for the generation of hydrogen energy as an alternative fuel source.Works Cited: Masa, J.; Weide, P.; Peeters, D.; Sinev, I.; Xia, W.; Sun, Z.; Somsen, C.; Muhler, M.; Schuhmann, W. Amorphous Cobalt Boride (Co2B) as a Highly Efficient Nonprecious Catalyst for Electrochemical Water Splitting: Oxygen and Hydrogen Evolution. Advanced Energy Materials 2016, 6 (12).Schlesingehr H.I.; Brown, H.C.; Finholt A.E.; Gilbreath J.R.; Hoekstra H.R.; Hyde E.L.; Sodium Borohydride, Its Hydolysis and its Use as a Reducing Agent in the Generation of Hydrogen; Chem. Soc., (1953), 75 (1), pp 215–219Clay Huff, Julia M. Long, Austin Heyman, and Tarek M. Abdel-Fattah Palladium Nanoparticle Multiwalled Carbon Nanotube Composite as Catalyst for Hydrogen Production by the Hydrolysis of Sodium BorohydrideACS Applied Energy Materials 2018 1 (9), 4635-4640 DOI: 10.1021/acsaem.8b00748Huff, C., Dushatinski, T., & Abdel-Fattah, T. M.. Gold nanoparticle/multi-walled carbon nanotube composite as novel catalyst for hydrogen evolution reactions. International Journal of Hydrogen Energy (2017) 42(30), 18985 18990.doi:10.1016/j.ijhydene.2017.05.226Semasko, M., Tamasauskaite-Tamasiunaite, L., Stalnioniene, I., Zieliene, A., Vaiciuniene, J., Simkunaite-Stanyniene, B., ... Norkus, E.. Hydrogen Generation via Sodium Borohydride Hydrolysis Using the Graphene Supported Platinum-Ruthenium-Cobalt Catalysts Prepared nu Microwave-Assisted Synthesis. ECS Transactions, (2015) 68(3), 37–44.doi:10.1149/06803.0037ecst Figure 1: SEM image of clusters of particles formed from graphene like sheets. These clusters range in size but are generally seen 25 microns or less Figure 1