ACS Applied Materials & Interfaces: new method to prepare carbon nanobelt

In this work, we present a one-step solution processed synthetic strategy at low temperature to prepare carbon-nanobelts-supported uniform Cu and Pd nanoclusters. It is found that Cu catalyzed the formation of carbon nanobelts. The prepared samples were used for the green synthesis of ammonia from nitrate by electrocatalysis. For the nitrate reduction reaction (NO₃RR), Cu–Pd/C nanobelts show higher activity than Cu/C nanobelts, achieving a high yield of ammonia of 220.8 μg mg_cat^–1 h^–1 with a Faradaic efficiency (FE) of 62.3% at −0.4 V vs RHE (reversible hydrogen electrode), while for the nitrite reduction reaction (NO₂RR), a high FE of 95% at −0.2 V vs RHE can be obtained for Cu/C nanobelts with the yield of ammonia increased with the negative shift of the applied potentials. Theoretical calculations demonstrated that Pd and Cu are responsible for hydrogen evolution reaction (HER) and NO₃RR, respectively.
green and scale-up synthesis of ammonia at ambient conditions. However, the performance has lagged due to lack of efficient electrocatalysts. In this work, we present the facile synthesis of uniform Cu nanodisks with exposed (111) facets as highly active electrocatalyst for electrochemical ammonia synthesis, delivering a high ammonia yield of 2.16 mg mg−1 cat h−1 and a maximum Faradaic efficiency of 81.1% at −0.5 V versus a reversible hydrogen electrode (RHE). The remarkable activity is originated from the surface reconstructed triatomic Cu clusters due to the cathodic deoxygenation process. As a result, the reconstructed surface shows enhanced affinity to the adsorption of nitrate ions which undergo successive break of three N−O bonds, followed by subsequent formation of three N−H bonds to finally form NH3. The present study provides the feasible preparation of Cu based advanced catalysts and a unique insight into the mechanism of nitrate electroreduction.