Highly Efficient AuPd/Carbon Nanotube Nanocatalysts for the Electro-Fenton Process

Development of novel nanocatalysts for the highly efficient in situ synthesis of H2O2 from H-2 and O-2 in the electro-Fenton (EF) process has potential for the remediation of water pollution. In this work, AuPd/carbon nanotube (CNT) nanocatalysts were successfully synthesized by the facile aggregation of AuPd bimetals on CNTs. Characterization by X-ray diffraction, transmission electron microscopy, and X-ray photoelectron spectroscopy indicated that pure AuPd bimetallic heterogeneous nanospheres (approximate to 20 nm) were well dispersed outside the CNTs, which resulted in better catalytic performance than Pd/CNTs alone: 0.36 M H2O2 was synthesized; 0.05 M Fe2+ optimally initiated the EF process due to the superior in situ Fe2+ regeneration; and the organic pollutant removal reached 100% at 37 min, with a pseudo-firstorder kinetic constant k(1)=0.051 min(-1). Moreover, structural insights before/after catalysis revealed that Au strengthened the construction of the nanocrystals, avoided negative deactivation caused by AuPd agglomeration, and immobilized the active Pd(111). The catalytic stability of AuPd/CNTs over ten cycles implied long durability and promising applications of this material.