Wednesday, 16 May 2018: 18:00
Room 606 (Washington State Convention Center)
In this work, we present a mass production method of nano-sized Ni catalyst using late transition metal oxides La2O3 and CeO2 as promoters on a carbon support. The Ni_La0.67Ce0.33O1.67/C catalyst was synthesized by co-precipitation for La0.67Ce0.33O1.67 and solvo-thermal for Ni, which are an easy method and capable of making higher activity and durability catalysts. La0.67Ce0.33O1.67 plays an important role in decreasing the size of the Ni particles and helps to improve the properties of the catalyst in reducing atmosphere by forming a solid solution. The Ni_La0.67Ce0.33O1.67/C catalyst recorded a lower overvoltage of 124 mV at a current density of 10 mA/cm2 and a higher long-term stability in 1 M KOH solution at room temperature compared to the Ni/C catalyst. It is suggested that La0.67Ce0.33O1.67 forms a partial alloy with Ni to prevent the detachment of Ni and acts as a barrier to prevent the migration of Ni. Based on the results of this study, a mechanism of Ni catalyst degradation was proposed.