Junji Nakamura

Nitrogen (N)-doped carbon materials exhibit high electrocatalytic activity for the oxygen reduction reaction (ORR), which is essential for several renewable energy systems. However, the ORR active site (or sites) is unclear, which retards further developments of high-performance catalysts. Here, we characterized the ORR active site by using newly designed graphite (highly oriented pyrolitic graphite) model catalysts with well-defined π conjugation and well-controlled doping of N species. The ORR

The oxygen reduction reaction (ORR) is a core reaction for electrochemical energy technologies such as fuel cells and metal-air batteries. ORR catalysts have been limited to platinum, which meets the requirements of high activity and durability. Over the last few decades, a variety of materials have been tested as non-Pt catalysts, from metal-organic complex molecules to metal-free catalysts. In particular, nitrogen-doped graphitic carbon materials, including N-doped graphene and N-doped carbon

The 12 wt% Pt-deposited carbon nanotube electrode gives 10% higher voltages than 29 wt% Pt-deposited carbon black and reduces the Pt usage by 60% in polymer electrolyte fuel cells with hydrogen and oxygen.

The structural sensitivity of the water-gas shift (WGS) reaction (CO + H2O → H2+ CO2) over metallic copper is addressed here by comparing its kinetics over the atomically clean Cu(110) surface with prior results for Cu(111). The surfaces were prepared and characterized with UHV surface analysis (AES, LEED, XPS), then transferred to an attached microreactor for medium-pressure [10–1000 Torr (1 Torr = 101 325/760 Pa)] kinetic measurements and finally returned to UHV for post-reaction surface analy

Kattel <i>et al</i> (Reports, 24 March 2017, p. 1296) report that a zinc on copper (Zn/Cu) surface undergoes oxidation to zinc oxide/copper (ZnO/Cu) during carbon dioxide (CO₂) hydrogenation to methanol and conclude that the Cu-ZnO interface is the active site for methanol synthesis. Similar experiments conducted two decades ago by Fujitani and Nakamura <i>et al</i> demonstrated that Zn is attached to formate rather than being fully oxidized.

The interactions of CO2 with a clean Cu(110) surface have been studied both in an ultrahigh-vacuum surface analytical chamber and in an attached, high-pressure cell. No adsorption or dissociation of CO2 was measured for exposures up to 350 L at 110 K and 250 K. Exposures of 65 to 650 Torr of CO2 at 400-600 K led to the build-up of atomically adsorbed oxygen according to the reaction CO2.g to COg+Oa at a rate which increased with temperature ( approximately 16 kcal mol-1) and decreased with react