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Two-dimensional (2D) layered catalysts have been considered as a class of ideal catalysts for hydrogen evolution reaction (HER) because of their abundant active sites with almost zero Gibbs energy change for hydrogen adsorption. Despite the promising performance, the design of stable and economic electrochemical catalyst based on 2D materials remains to be resolved for industrial-scale hydrogen production. Here, we report layered platinum tellurides, mitrofanovite Pt3Te4, which serves as an efficient and stable catalyst for HER with an overpotential of 39.6 mV and a Tafel slope of 32.7 mV/dec together with a high current density exceeding 7000 mA/cm2. Pt3Te4 was synthesized as nanocrystals on a metallic molybdenum ditelluride (MoTe2) template by a rapid electrochemical method. X-ray diffraction and high-resolution transmission microscopy revealed that the Pt3Te4 nanocrystals have a unique layered structure with repeated monolayer units of PtTe and PtTe2. Theoretical calculations exhibit that Pt3Te4 with numerous edges shows near-zero Gibbs free-energy change of hydrogen adsorption, which shows the excellent HER performance as well as the extremely large exchange current density for massive hydrogen production.

Solid oxide fuel cells (SOFCs) have been regarded as a promising the energy conversion device from chemical energy of fuel, because of numerous advantages, such as high energy conversion efficiency, multi fuel capability, and no emission of pollutants [1]. Co-based perovskite oxides have spotlighted. For the cathode materials of SOFCs due to low over-potential for the oxygen reduction reaction (ORR), thus resulting in high performance of SOFCs [2]. However, the large dissimilarity of thermal expansion coefficient (TEC) between Co-based perovskites and typical yttria-stabilized zirconia (YSZ) and samarium-doped ceria (SDC) electrolytes result in degrading of long-term durability of SOFCs. The TECs’ of Co-based perovskite oxides are but the general electrolyte, such as YSZ’s TEC is and, indicating a huge difference between them [3]. Meanwhile, lanthanum nickelate, Lan+1NinO3n+1, may have high thermal stability than Co-based perovskites, because the TEC of Lan+1NinO3n+1 is , similar to the YSZ electrolyte [4]. In this work, hence anode-supported cells are fabricated with SDC electrolytes, Ni-cermet anode, and lanthanum nickelate cathode. To investigate the performance and durability of cathode materials, I-V measurements and load cycling testing methods are used to check the performance and durability of cells. The electrochemical impedance spectroscopy measurements are also performed for the electrochemical analysis. In addition, various physicochemical analysis tools are used, such as SEM, TEM, and XRD as the postmortem analysis [5]. References [1] K.T. Lee, E.D. Wachsman, Science 334 (2011) 935. [2] E. Boehm, J.-C. Grenier, Solid State Sciences 5 (2003) 973. [3] S. Pang, X. Xi, J. Power Sources 326 (2016) 176. [4] R.K. Sharma, E. Djurado, J. Power Sources 325 (2016) 337. [5] T.H Lee, J.-Y. Park. J. Power Sources 331 (2016) 495 Keywords : Solid oxide fuel cells; Lanthanum nickelate; Thermal Expansion Coefficient; Durability * Corresponding authors: jyoung@sejong.ac.kr (J.-Y. Park)