Nanoscopic Ni Interfaced with Oxygen Conductive Supports: Link between Electrochemical and Catalytic Studies

Abstract

Nickel nanoparticles (NPs) of ~70 nm diameter were tested for their catalytic and electrochemical performance when free-standing or supported at 1 wt.% on CeO 2 or YSZ conductive supports. Ni/CeO 2 showed a high complete ethylene conversion (43%) followed by Ni/YSZ (38%) and then free-standing Ni (5%) at 350 o C. The Tafel plots allowed us to find the exchange current density, i o , of the catalysts. Using i o , the self-induced Faradaic efficiency, Λ MSI , was calculated for the two supported catalysts and was found to be almost the double for Ni/CeO 2 compared to Ni/YSZ. The inverse relationship between i o and the catalytic rate of Ni, Ni/YSZ and Ni/CeO 2 is similar to the one for the noble Pt, Ru and Ir catalysts reported previously. This correlation suggests that for nanoscopic Ni catalysts interfaced with oxygen conducting ceramics, the mechanism of metal-support interaction (MSI) is functionally identical to that of electrochemical promotion of catalysis (EPOC).

Theoretical insight into the origin of the electrochemical promotion of ethylene oxidation on ruthenium oxide

“…Catalytic measurements were carried out at atmospheric pressure in the single-chamber capsule described in our previous work such as all electrodes are under the same gaseous conditions 77,78 . The working electrode side of the electrolyte was pressed against a gold mesh (1 cm 2 ) that served as a current collector, while the counter and reference electrodes were pressed directly against gold wires 79 . Two type K thermocouples (Omega Ò ) were placed in the vicinity of the Please do not adjust margins Please do not adjust margins electrochemical cell, one for temperature control and one for data acquisition.…”

Electrochemical Promotion of Nanostructured Palladium Catalyst for Complete Methane Oxidation

“…Catalytic measurements were carried out at atmospheric pressure in the single-chamber capsule reactor reported earlier [31,32]. The working electrode side of the electrolyte was pressed against a gold mesh (1 cm 2 ) that served as a current collector, while the counter and reference electrodes were pressed directly against gold wires [33]. Two type K thermocouples (Omega ® , Quebec, Canada) were placed in vicinity of the electrochemical cell, one for temperature control and one for data acquisition.…”

Electrochemical control of the RWGS reaction over Ni nanoparticles deposited on yttria stabilized zirconia

“…A possible explanation for this behavior is that Ni nanoparticles can exhibit magnetic properties, which increases their tendency to agglomerate over time in the colloidal solution. 34…”