Selective Catalytic Reduction of Nitrogen Oxides with Hydrogen (H2‐SCR‐DeNOx) over Platinum‐Based Catalysts.

Selective catalytic reduction of NO<italic>x</italic> with hydrogen (H2‐SCR‐DeNO<italic>x</italic>) is applied among other techniques (i. e., SCR‐DeNO<italic>x</italic> by applying NH3 or hydrocarbons as reducing agents) to control nitrogen oxides from mobile and stationary sources. As a zero carbon technology, which efficiently reduces NO<italic>x</italic> below 200 °C, H2‐SCR‐DeNO<italic>x</italic> has gained attention in installations and plants with H2 availability. The catalytic properties of platinum‐based catalysts with the main focus on the applied supports (i. e., inorganic oxides and zeolites) are given in detail. Another focus concerns on how the feed composition affects catalytic properties, specifically the levels of oxygen, water vapor, sulfur, and carbon oxides present in the exhausts. The major challenges are presented in enhancing the N2 selectivity and stability of catalysts at low temperatures without affecting their activity. Promising research prospects in this area include the development of catalysts with improved dispersion and distribution of Pt particles. In addition, the proposed bi‐functional (dual‐function) reaction mechanism over Pt‐containing catalysts, together with the adsorption/dissociation mechanism and NO oxidation/reduction mechanism, is described and critically reviewed. Also, Pd‐based catalysts are briefly discussed. It is expected that the review will provide broad insights into the design and optimization of catalysts in the H2‐SCR‐DeNOx. [ABSTRACT FROM AUTHOR]