硝酸イオン除去に及ぼす銅-白金触媒の表面組成の影響
1999 年 50 巻 12 号 p. 1137-1141
詳細
1999 年 50 巻 12 号 p. 1137-1141
We studied nitrate reduction with hydrogen in Cu-Pt black catalysts with various surface compositions. Nitrate removal is extremely slow in Pt and Cu catalysts alone, but enhanced in Pt black catalysts with Cu atoms. Hydrogen is oxidized at Pt sites, and nitrate reduced at Cu sites. We examined the relationship between nitrate concentration and reaction time and found that nitrate removal in Cu-Pt black catalysts is apparently a first-order reaction. Cu coverage affects selectivity of the products of the Cu-Pt black catalyst. The main product of nitrate reduction was nitrite in Pt black catalysts with Cu coverage of about 0.6, where nitrite would be reduced to nitrogen, though the reaction is slow. The maximum rate constant is 5.3×10-6m min-1 in Pt black catalysts with Cu coverage of about 0.85, where the main nitrate reduction products were ammonia and nitrogen.
