Paper-structured catalyst for catalytic NOxNOx removal from combustion exhaust gas

Platinum/aluminum oxide (Pt/Al2O3) catalyst powders were successfully fabricated to give paper-like composites using ceramic fibers by a papermaking technique. As-prepared composites, called paper-structured catalysts, possessed a fiber-network microstructure on which the Pt/Al2O3 powders were scattered. The paper-structured catalysts were subjected to a catalytic reduction process of nitrogen oxides (NOxNOx), and demonstrated a higher performance than the original Pt/Al2O3 powders and a commercial honeycomb catalyst. A simple mixture of catalyst powders and inorganic fibers was not effective, suggesting that the characteristic porous microstructure (average pore size: ca. 20μm, porosity: ca. 70%) in the paper-structured catalyst possibly contributed to the efficient NOxNOx reduction. Besides, the paper-structured catalyst exhibited a quick response in the catalytic NOxNOx reduction at a rapidly increasing reaction temperature as compared to the honeycomb catalyst. The paper composite is flexible, lightweight and easy to handle; thus the paper-structured catalyst is expected to be a promising catalytic material for exhaust gas purification.