High catalytic activity for formaldehyde oxidation of AgCo/APTES@MCM-41 prepared by two steps method

• Highly active AgCo/APTES@MCM-41 catalysts are prepared by two steps method.
• AgCo/APTES@MCM-41 with Ag/Co = 3/1 ratio shows the best activity for HCHO oxidation.
• The formed SMMI and the interface between Ag and Co are essential for the reaction.
• The SMMI results in the high Co3+/Co2+ ratio and good low-temperature reducibility.
• High concentration of surface oxygen species is beneficial for HCHO oxidation.

We reported here a novel synthesis procedure to prepare a highly active bimetallic AgCo/APTES@MCM-41 catalyst. Complete oxidation of formaldehyde was achieved at temperature as low as 90 °C over the bimetallic catalysts with Ag/Co = 3/1 (mass ratio). N2 isotherms, small-angle XRD results suggested that both Ag and Co species were well dispersed on the support, and the pore structure of the support was not destroyed after introducing the active metal. The formation of the strong metal–metal interaction (SMMI) between Ag and Co in the bimetallic catalysts due to the electron transfer between each other resulted in the high Co3+/Co2+ ratio and good low-temperature reducibility. And more surface active oxygen species (Osurf) formed on the surface of the bimetallic catalysts. All these factors gave rise to the high formaldehyde catalytic oxidation activity in AgCo bimetallic catalysts. The possible structure changes of bimetallic catalysts and the reaction path for the complete oxidation of formaldehyde over AgCo bimetallic catalyst was also proposed.

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