Regulating coordination state for production of effective denitrification catalyst

Abstract

In the field of selective catalytic reduction of nitrogen oxide, metal-species and loading-amount regulations were usually investigated to increase the catalytic activity. For the first time, this work investigated the influence of metal coordination state on the catalytic activity. Catalysts with different coordination states were compared by experiments and theoretical calculations. With the increase of coordination state, crystallinity improved, lone-pair-electron amount increased from 7.0∗104 to 1.5∗106, and catalytic-enter ability for electron donating enhanced from 0.376 to 0.430 |e−|. In comparison, oxide-state catalyst only showed a charge of 0.294 |e−|. As a result, the catalytic activity of oxide state was only 39.45% at 350 °C. The activity increased to 59.46, 76.75, and 98.62% in poor, weak, and good coordination state, respectively. If this result was applied in producing honeycomb catalyst, adding ligand increased the total price by 4%. However, the total cost was reduced by 48% for end users since increased activity decreased usage amount. After all, main results of this work will help to produce a more effective catalyst with a same metal-loading amount by controlling coordination state, which is in favor of both industrial and academic fields.