Au–Pd/3DOM Co 3 O 4 : Highly active and stable nanocatalysts for toluene oxidation

Abstract The polymethyl methacrylate-templating and polyvinyl alcohol-protected reduction routes were adopted to prepared three-dimensionally ordered macroporous (3DOM) Co 3 O 4 and its supported gold–palladium alloy ( x AuPd/3DOM Co 3 O 4 , x  = 0.50–1.99 wt% and Au/Pd mass ratio = 1:1) nanocatalysts. The 3DOM Co 3 O 4 supported Au–Pd samples performed much better than supported single Au or Pd samples, with the 1.99AuPd/3DOM Co 3 O 4 sample showing the best performance: the T 10% , T 50% , and T 90% (temperatures required for achieving toluene conversions of 10%, 50%, and 90%) were 145, 164, and 168 °C at a space velocity of 40,000 mL/(g h), respectively. The 3DOM Co 3 O 4 supported Au–Pd nanocatalysts also exhibited better catalytic stability and more moisture-tolerant ability than the supported Au or Pd samples for toluene oxidation. The apparent activation energies (33–41 kJ/mol) over x AuPd/3DOM Co 3 O 4 were much lower than those (52–112 kJ/mol) over 3DOM Co 3 O 4 and supported single Au or Pd samples, with the 1.99AuPd/3DOM Co 3 O 4 sample exhibiting the lowest apparent activation energy (33 kJ/mol). It is concluded that better oxygen activation ability and stronger noble metal–3DOM Co 3 O 4 interaction were responsible for the excellent catalytic performance of 1.99AuPd/3DOM Co 3 O 4 .