Capturing the Role of Phosphate in the Ni-PY5 Catalyzed Water Oxidation

Pan, Hui1; Duan, Lele2,3; Liao, Rong-Zhen1

2019-10-24

10.1002/cctc.201901439

ChemCatChem   影响因子和分区

1867-3880

1867-3899

The mononuclear Nickel complex Ni-PY5 [PY5=2, 6-bis(1,1-bis(2-pyridyl)ethyl)pyridine] has been disclosed to catalyze water oxidation electrochemically with an applied potential of 1.5 V at pH 10.8 in aqueous phosphate buffer solution. Density functional calculations were used to elucidate the reaction mechanism of water oxidation catalyzed by this nickel complex and to capture the role of the phosphate. The calculations demonstrated that the oxidations of the starting [OH2-Ni-II-PY5](2+) complex by two sequential proton-coupled electron-transfer processes lead to the formation of a key intermediate [O=Ni-IV-PY5](2+). O-O bond formation then takes place through a water nucleophilic attack on the high-valent Ni-IV=O moiety of the catalyst, facilitated by a hydrogen phosphate anion, with a total barrier of 11.5 kcal mol(-1). The calculated barrier agrees very well with the experimental turnover frequency of about 2000 s(-1), which corresponds to a barrier of 12.9 kcal mol(-1). The calculated deuterium kinetic isotope effect of 1.99 is also in excellent agreement with the experimental value of 2.06. Finally, we also predicted the catalytic activity of other PY5-based first-row transition metal complexes, namely, involving Mn, Fe, Co and Cu. The calculations showed that the Mn, Fe, Co complexes have higher barrier for water oxidation, while the Cu complex has lower barrier and higher water oxidation activity compared with the Ni complex.

density functional calculations water oxidation nickel reaction mechanism

SCI ; EI

英语

其他

Fundamental Research Funds for the Central Universities[2017KFKJXX014]

Chemistry

Chemistry, Physical

WOS:000492066700001

WILEY-V C H VERLAG GMBH

20194507649165

Catalysis ; Catalyst activity ; Cobalt compounds ; Copper compounds ; Density functional theory ; Iron compounds ; Manganese removal (water treatment) ; Metal complexes ; Nickel ; Oxidation ; Transition metals

Water Treatment Techniques:445.1 ; Metallurgy and Metallography:531 ; Nickel:548.1 ; Chemical Reactions:802.2 ; Chemical Agents and Basic Industrial Chemicals:803 ; Chemical Products Generally:804 ; Inorganic Compounds:804.2 ; Probability Theory:922.1

Web of Science

1.Huazhong Univ Sci & Technol, Key Lab Mat Chem Energy Convers & Storage, Sch Chem & Chem Engn,Hubei Key Lab Mat Chem & Ser, Minist Educ,Hubei Key Lab Bioinorgan Chem & Mater, Wuhan 430074, Hubei, Peoples R China
2.Southern Univ Sci & Technol SUSTech, Dept Chem, Shenzhen 518055, Peoples R China
3.Southern Univ Sci & Technol SUSTech, Shenzhen Grubbs Inst, Shenzhen 518055, Peoples R China

Pan, Hui,Duan, Lele,Liao, Rong-Zhen. Capturing the Role of Phosphate in the Ni-PY5 Catalyzed Water Oxidation[J]. ChemCatChem,2019,12(1):219-226.

Pan, Hui,Duan, Lele,&Liao, Rong-Zhen.(2019).Capturing the Role of Phosphate in the Ni-PY5 Catalyzed Water Oxidation.ChemCatChem,12(1),219-226.

Pan, Hui,et al."Capturing the Role of Phosphate in the Ni-PY5 Catalyzed Water Oxidation".ChemCatChem 12.1(2019):219-226.