Electrocatalytic activity and volatile product selectivity for nitrate reduction at tin-modified Pt(100), Pd(100) and Pd–Pt(100) single crystal electrodes in acidic media

We prepared Sn-modified Pt(100), Pd(100) and Pd–Pt(100) single crystal electrodes and investigated the nitrate reduction reaction (NO3RR) activity and the product selectivity for them using online electrochemical mass spectroscopy (OLEMS), also known as differential electrochemical mass spectroscopy (DEMS). OLEMS measurements allowed us to quantify volatile products of N2, N2O and NO and confirm the production of N2 at Sn/Pd(100) but not at Sn/Pt(100). Pd-doping to Pt(100) with a 3 atomic % increased the product selectivity for the NO3RR to N2. These results indicate that the presence of Pd in the (100) surface is the key to produce N2, which seems to be related to the hydrogen adsorption energy to the metal surface. The suppression of hydrogenation of intermediate species at the electrode surface could lead to the production of N2. This work will guide us to understand N2 production mechanism for the NO3RR and develop highly selective electrocatalysts for denitrification

Cation Effects on ORR Activity on Low-index Planes of Pd in Alkaline Solution

The oxygen reduction reaction (ORR) has been studied on low-index planes of Pd in 0.05 M XOH (X = Li, Na, K, and Cs) solutions to determine the effects of cations on ORR activity. The order of ORR activity is Pd(110) ＜ Pd(100) ＜ Pd(111) in all solutions. This order differs from that in HClO4: Pd(110) ＜ Pd(111) ≪ Pd(100). Cationic species do not affect the ORR activity on Pd(110) and Pd(100). In contrast, the ORR activity of Pd(111) increases in the order of Li+ ＜ Na+ ＜ K+ ＜ Cs+. The lower the cation hydration energy, the higher the ORR activity on Pd(111), as is also the case on Pt(111). The ORR activity of Pd(111) in CsOH is 1.8 times higher than that of Pd(100) in HClO4

Electrocatalytic activity and volatile product selectivity for nitrate reduction at tin-modified Pt(100), Pd(100) and Pd–Pt(100) single crystal electrodes in acidic media

We prepared Sn-modified Pt(100), Pd(100) and Pd–Pt(100) single crystal electrodes and investigated the nitrate reduction reaction (NO3RR) activity and the product selectivity for them using online electrochemical mass spectroscopy (OLEMS), also known as differential electrochemical mass spectroscopy (DEMS). OLEMS measurements allowed us to quantify volatile products of N2, N2O and NO and confirm the production of N2 at Sn/Pd(100) but not at Sn/Pt(100). Pd-doping to Pt(100) with a 3 atomic % increased the product selectivity for the NO3RR to N2. These results indicate that the presence of Pd in the (100) surface is the key to produce N2, which seems to be related to the hydrogen adsorption energy to the metal surface. The suppression of hydrogenation of intermediate species at the electrode surface could lead to the production of N2. This work will guide us to understand N2 production mechanism for the NO3RR and develop highly selective electrocatalysts for denitrification