title: Effect of promoter and noble metals and suspension pH on catalytic nitrate reduction by bimetallic nanoscale Fe(0) catalysts.
abstract: Experiments were conducted to investigate the effect of experimental factors (types of promotor and noble metals, H2 injection, and suspension pH) on catalytic nitrate reduction by bimetallic catalysts supported by nanoscale zero-valent iron (NZVI). NZVI without H2 injection showed 71% of nitrate reduction in 1 h. Cu/NZVI showed the almost complete nitrate reduction (96%) in 1 h, while 67% of nitrate was reduced by Ni/NZVI. The presence of noble metals (Pd and Pt) on Cu/NZVI without H2 injection resulted in the decrease of removal efficiency to 89% and 84%, respectively, due probably to the electron loss of NZVI for formation of metallic Pd and Pt. H2 injection into Cu-Pd/NZVI suspension significantly improved both catalytic nitrate reduction (>97% in 30 min) and N2 selectivity (18%), indicating that adsorbed H on active Pd sites played an important role for the enhanced nitrate reduction and N2 selectivity. The rapid passivation of NZVI surface resulted in a dramatic decrease in nitrate reduction (79-28%) with an increase in N2 selectivity (8-66%) as the suspension pH increased from 8 to 10.
authors.affiliation: a Institute for Nuclear Waste Disposal , Karlsruhe Institute of Technology , Karlsruhe , Germany.|b Department of Civil and Environmental Engineering , Korea Advanced Institute of Science and Technology , Yuseong-gu , Daejeon , Republic of Korea.
authors.forename: Sungjun
authors.initials: S
authors.lastname: Bae
authors.affiliation: b Department of Civil and Environmental Engineering , Korea Advanced Institute of Science and Technology , Yuseong-gu , Daejeon , Republic of Korea.
authors.forename: Shanawar
authors.initials: S
authors.lastname: Hamid
authors.affiliation: c GS Engineering and Construction , Jongno-gu , Seoul , Republic of Korea.
authors.forename: Junyoung
authors.initials: J
authors.lastname: Jung
authors.affiliation: d Department of Nuclear and Quantum Engineering , Korea Advanced Institute of Science and Technology , Yuseong-gu , Daejeon , Republic of Korea.
authors.forename: Youngho
authors.initials: Y
authors.lastname: Sihn
authors.affiliation: b Department of Civil and Environmental Engineering , Korea Advanced Institute of Science and Technology , Yuseong-gu , Daejeon , Republic of Korea.
authors.forename: Woojin
authors.initials: W
authors.lastname: Lee
mesh_terms: D002384:Catalysis; D003300:Copper / Q000737:chemistry; D004867:Equipment Design; D006859:Hydrogen / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000737:chemistry*; D009566:Nitrates / Q000737:chemistry / Q000302:isolation & purification*; D010084:Oxidation-Reduction; D010165:Palladium / Q000737:chemistry*; D010984:Platinum / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000302:isolation & purification*; D018508:Water Purification / Q000295:instrumentation / Q000379:methods*
chemical_list: D009566:Nitrates; D014874:Water Pollutants, Chemical; D010984:Platinum; D010165:Palladium; D003300:Copper; D006859:Hydrogen; D007501:Iron
keywords: H2 injection; NZVI; Nitrate; bimetallic catalyst; pH