A new supported Cu/Pd bimetallic nanoparticles composites prestoring reductant for nitrate removal: high reactivity and N2 selectivity

Catalytic hydrogen reduction appears to be a promising strategy for nitrate removal. However, the danger and low utilization of H-2 are the disadvantages of catalytic hydrogen reduction. Sodium borohydride (NaBH4), considered a potential candidate for hydrogen storage, has been investigated as an electron source for the catalytic reduction of contaminants. However, extensive use of NaBH4 makes commercialization costly and causes environmental pollution. In this study, we prepared supported Cu/Pd bimetallic nanoparticles that could prestore hydrogen. No additional reducing agent was required during the nitrate reduction process. The performance and mechanism of Cu/Pd bimetallic nanoparticles for nitrate reduction are discussed. Good performance was obtained with high reactivity (99.04% nitrate removal efficiency) and high selectivity for N-2 (94.71%). The Cu/Pd bimetallic catalyst could be recovered by NaBH4 for 5 cycles. Moreover, a 97.49% nitrate removal efficiency was obtained for actual wastewater, indicating good prospects for nitrate reduction applications.