Song, IK Kim, HS Chun, MS 2024-01-21T08:13:39Z 2024-01-21T08:13:39Z 2021-09-03 2003-09 0256-1115 https://pubs.kist.re.kr/handle/201004/138278 UV-Visible spectroscopy and scanning tunneling microscopy (STM) studies were performed to explore reduction potentials of cation-exchanged Keggin-type heteropolyacid (HPA) catalysts. Absorption band edge and negative differential resistance (NDR) peak voltage of cation-exchanged HPA samples determined by UV-Visible spectroscopy and STM, respectively, were colsely related to their reduction potentials. It was observed that HPAs with higher reduction potentials showed absorption band edges at longer wave lengths and exhibited NDR peak voltages at less negative applied values. The reduction potentials of cation-exchanged HPA catalysts could also be correlated with the electronegativities of counter-cations. Substitution of more electronegative counter-cations increased reduction potentials of the HPAs. The NDR peak voltage and the absorption band edge of HPAs could be utilized as a correlating parameter for their reduction potentials. English KOREAN INSTITUTE CHEMICAL ENGINEERS SCANNING-TUNNELING-MICROSCOPY DIFFERENTIAL RESISTANCE BEHAVIOR ACID SPECTROSCOPY CATALYSIS MONOLAYERS OXIDATION METHANOL REDOX BLUES On the reduction potential of cation-exchanged heteropolyacids (HPAs) Article 10.1007/BF02697286 1 KOREAN JOURNAL OF CHEMICAL ENGINEERING, v.20, no.5, pp.844 - 849 KOREAN JOURNAL OF CHEMICAL ENGINEERING 20 5 844 849 scie scopus kci 000185753500009 2-s2.0-0344961258 Chemistry, Multidisciplinary Engineering, Chemical Chemistry Engineering Article SCANNING-TUNNELING-MICROSCOPY DIFFERENTIAL RESISTANCE BEHAVIOR ACID SPECTROSCOPY CATALYSIS MONOLAYERS OXIDATION METHANOL REDOX BLUES heteropolyacid (HPA) reduction potential NDR absorption edge