H2O2穩定性的密度泛函研究

程 學 禮

(泰山學院 化學化工學院，山東 泰安 271000)

1 前言

雙氧水(H2O2)是一種清潔氧化劑而被廣泛用于造紙和化學合成[1]，能夠參與多種氧化還原反應[2-4].H2O2還常被用于有機污染物的降解[5-7]，著名的芬頓反應就是用H2O2和Fe2+的混合溶液氧化有機化合物，特別是難降解有機污染物[8-9].

H2O2可以通過氫氣和氧氣直接反應或氧氣電還原等方法低成本合成[10-11].然而，無論在氣相還是溶液中H2O2均不穩定，易分解釋放氧氣(ΔH=-98.23 kJ/mol)；H2O2對光照敏感，雙氧水在λ= 275-366nm下均可分解[12-13].在金屬陽離子、碘離子和金屬氧化物催化下，H2O2能夠快速分解[14-17].一般情況下，H2O2分解為2個羥基自由基參與反應，因此，O-O鍵長的變化在H2O2分解過程中將扮演重要角色.

2 計算方法

3 結果與討論

3.1 基態結構

圖1 B3LYP和M06-2X方法結合得到的分子結構(鍵長的單位是nm，括號內為氣相鍵長)

3.2 發射光譜

表1 TD-M062X模擬得到的4種結構發射光譜的最大發射波長λmax(振子強度f)和躍遷軌道(躍遷貢獻比). λmax以nm為單位.方括號內數據為氣相數據

3.3 激發態結構

圖2 T1態優化結構參數

4 結論

[參考文獻]

[1]Kim S., Moon G., Kim H., Mun Y., Zhang P., Lee J., Choi W. Selective charge transfer to dioxygen on KPF6-modified carbon nitride for photocatalytic synthesis of H2O2under visible light[J]. J.Catal.,2018(357):51-58.

[2]Yin G.,Ni Y. Mechanism of the ClO2generation from the H2O2-HClO3reaction[J].Can.J.Chem.Eng.,2000,78(4):827-833.

[3]Jena N. R.,Mishra P. C. Mechanisms of formation of 8-oxoguanine due to reactions of one and two OHradicals and the H2O2molecule with guanine: A quantum computational study[J].J.Phys.Chem.B,2005,109(29):14205-14218.

[4]Das S., Bhattacharyya J.,Mukhopadhyay S. Mechanistic studies on oxidation of hydrogen peroxide by an oxo-bridged diiron complex in aqueous acidic media[J].Dalton Trans.,2008(46):6634-6640.

[5]Gain S., Mishra R., Mukhopadhyay S., Banerjee R. Mechanistic studies on oxidation of hydrogen peroxide and hydrazine by a metal-bound superoxide[J].Inorg.Chim.Acta,2011(373):311-314.

[6]朱承駐,秦艷,周元祥,董文博,侯惠奇.266 nm光照下水溶液中氯苯與H2O2的反應機理研究 [J].化學學報,2007,65(5):451-458.

[7]Merényi G, Lind J., Naumov S.,von Sonntag C. Reaction of ozone with hydrogen peroxide (peroxone process): A revision of current mechanistic concepts based on thermokinetic and quantum-chemical consideration[J].Environ.Sci.Technol.,2010,44(9):3505-3507.

[8]Perez-Benito J.F. Iron(III)-hydrogen peroxide reaction: Kinetic evidence of a hydroxyl-mediated chainmechanism[J].J.Phys.Chem.A,2004,108(22):4853-4858.

[9]Navalon S., Dhakshinamoorthy A., Alvaro M., Garcia H. Heterogeneous Fenton catalysts based on activatedcarbon and related materials[J].ChemSusChem,2011,4(12):1712-1730.

[10]Zhao K., Su Y.,QuanX., Liu Y.,ChenS.,YuH. Enhanced H2O2production by selective electrochemical reduction of O2on fluorine-doped hierarchically porous carbon[J].J.Catal.,2018(357):118-126.

[11]Wilson N.M.,Priyadarshini P.,Kunz S.,Flaherty D.W. Direct synthesis of H2O2on Pd and AuxPd1clusters: Understanding the effects of alloying Pd with Au[J].J.Catal.,2018(357):163-175.

[12]Odochian L., Iancu L., Humelnicu I., Mocanu A.M., Baiceanu A. Contributions to the reaction mechanism of photochemicaldecomposition of hydrogen peroxide in aqueous solution[J]. Rev. Chim. (Bucharest),2011,62(10):1012-1016.

[13]Nedrygailov I.I., Lee C., Moon S.Y., Lee H., Park J.Y. Hot electrons at solid liquid interfaces: A large chemoelectriceffect during the catalytic decomposition of hydrogen peroxide[J].Angew.Chem.Int. Ed.,2016,55(36):10859-10862.

[14]Dalmázio I., Moura F.C. C., Ara jo M.H., Alves T.M. A., Lago R.M., de Lima G.F., Duarte H.A.,R.Augusti. The iodide-catalyzed decomposition of hydrogen peroxide: Mechanistic details of an oldreaction as revealed by electrospray ionization mass spectrometry monitoring[J].J. Braz. Chem. Soc., 2008,19(6):1105-1110.

[15]Voloshin Y., Manganaro J., Lawal A. Kinetics and mechanism of decomposition of hydrogen peroxide over Pd/SiO2catalyst[J]. Ind. Eng. Chem. Res.,2008,47(21):8119-8125.

[16]Do S.-H.,Batchelor B.,Lee H.-K.,Kong S.-H. Hydrogen peroxide decomposition on manganese oxide (pyrolusite): Kinetics, intermediates, and mechanism[J].Chemosphere,2009(75):8-12.

[17]Zhao Y., Chen Z., Shen X., Zhang X. Kinetics and mechanisms of heterogeneous reaction of gaseoushydrogen peroxide on mineral oxide particles[J].Environ. Sci. Technol.,2011,45(8):3317-3324.

[18]Verlet J. R. R., Bragg A. E., Kammrath A., Cheshnovsky O., Neumark D. M. Observation of largewater-cluster anions withsurface-bound excess electrons[J].Science,2005,307(5706):93-96.

[19]Turi L., Sheu W., Rossky P.J. Characterization of excesselectrons in water-cluster anions by quantum simulations[J].Science,2005,309(5736):914-917.

[20]Tsai C. J.,Jordan K. D. Theoretical study of the (H2O)6cluster[J].Chem.Phys.Lett.,1993(213):181-188.

[21]Pedulla J. M., Vila F., Jordan K. D. Binding energy of the ring form of (H2O)6: Comparison of the predictions of conventional and localized-orbital MP2 calculations[J].J.Chem.Phys.,1996,105(24):11091-11099.

[22]Pedulla J. M., Kim K., Jordan K. D. Theoretical study of the n-body interaction energies of the ring, cage and prism forms of (H2O)6[J].Chem.Phys.Lett.,1998(291):78-84.

[23]Balasubramanian K. Nonrigid group theory, tunneling splittings, and nuclear spin statistics of waterpentamer: (H2O)5[J].J.Phys.Chem.A,2004,108(26):5527-5536.

[24]Jiang J., Wang Y., Chang H., Lin S.H., Lee Y.T., Niedner-Schatteburg G., Chang H. Infrared spectra of H+(H2O)5-8clusters: Evidence for symmetricproton hydration[J].J.Am.Chem.Soc.,2000,122(7):1398-1410.

[25]Dahms F., Costard R., Pines E., Fingerhut B.P., Nibbering E.T. J., Elsaesser T. The hydrated excess proton in the Zundel cation H5O2+: The role of ultrafast solvent fluctuations[J].Angew.Chem.Int. Ed.,2016,55(36):10600-10605.

[26]Arias C., Mata F., Perez-Benit J.F. Kinetics and mechanism of oxidation of iodide ion by the molybdenum(VI)-hydrogen peroxide system[J].O.Can.J.Chem.,1990,68(9):1499-1503.

[27] Moin S.T., Hofer T.S., Randolf B.R., Rode B.M. An ab initioquantum mechanical charge eld molecular dynamics simulation of hydrogen peroxide in water[J].Comput.Theor.Chem.,2012(980):15-22.