Pd-Cu双金属催化剂上加氢反应的仲氢诱导超极化研究

doi:10.11938/cjmr20182646

摘要/Abstract

摘要： 本文通过多相催化-仲氢诱导超极化（HET-PHIP）核磁共振（NMR）技术研究了Pd-Cu/SiO₂双金属催化剂上丙炔选择性加氢反应.首先利用等体积浸渍法和连续浸渍法合成了一系列不同Pd/Cu比例和形貌的Pd-Cu/SiO₂双金属催化剂.通过ALTADENA（Adiabatic Longitudinal Transport After Dissociation Engenders Net Alignment）方法发现，催化剂的Pd/Cu比例和形貌均对PHIP的极化效率有较大影响.随着Pd-Cu双金属催化剂中Pd比例的增大，PHIP极化效率降低，同时反应活性增强.在同Pd/Cu比例下，相对于等体积浸渍法，连续浸渍法制备的层叠形貌催化剂具有较弱的极化效率以及较强的催化活性，这是由于催化剂表面暴露出的Pd数量增多，导致催化活性增强；同时单个Pd集簇表面积增大，使得氢原子移动范围扩大，从而造成极化效率降低.

关键词: 仲氢诱导超极化(PHIP), 双金属催化剂, 丙炔加氢反应, 信号增强, 核磁共振(NMR)

Abstract: Hydrogenation reaction of propyne on Pd-Cu bimetallic catalysts was studied using the heterogeneous parahydrogen-induced polarization (PHIP) nuclear magnetic resonance (NMR) technique. Incipient-wetness impregnation and sequential impregnation were used to prepare Pd-Cu/SiO₂ bimetallic catalysts with different composition and morphology. With the ALTADENA (Adiabatic Longitudinal Transport After Dissociation Engenders Net Alignment) method, it was observed that both the composition and morphology of the bimetallic catalysts had significant influence on the efficiency of PHIP. The catalysts with lower Pd/Cu atom ratio had lower activity but higher polarization efficiency. Compared to isometric impregnation method, the palladium atoms in the Pd-Cu/SiO₂ catalyst synthesized with the sequential impregnation method mostly stayed on the surface of bimetallic nanoparticles, generating larger Pd ensembles and leading to higher catalytic activity and lower polarization efficiency.

Key words: parahydrogen-induced polarization (PHIP), bimetallic catalyst, propyne hydrogenation reaction, signal intensity enhancement, nuclear magnetic resonance (NMR)

中图分类号:

O482.53

王伟宇, 胡涵, 徐君, 邓风. Pd-Cu双金属催化剂上加氢反应的仲氢诱导超极化研究[J]. 波谱学杂志, 2018, 35(3): 269-279.

WANG Wei-yu, HU Han, XU Jun, DENG Feng. Hydrogenation Reaction on Pd-Cu Bimetallic Catalysts: A Parahydrogen-Induced Polarization Study[J]. Chinese Journal of Magnetic Resonance, 2018, 35(3): 269-279.

参考文献

[1] BOWERS C R, WEITEKAMP D P. Transformation of symmetrization order to nuclear-spin magnetization by chemical-reaction and nuclear-magnetic-resonance[J]. Phys Rev Lett, 1986, 57(21):2645-2648.
[2] BOWERS C R, WEITEKAMP D P. Para-hydrogen and synthesis allow dramatically enhanced nuclear alignment[J]. J Am Chem Soc, 1987, 109(18):5541-5542.
[3] EISENSCHMID T C, KIRSS R U, DEUTSCH P P, et al. Para hydrogen induced polarization in hydrogenation reactions[J]. J Am Chem Soc, 1987, 109(26):8089-8091.
[4] REINERI F, AIME S, GOBETTO R, et al. Role of the reaction intermediates in determining PHIP (parahydrogen induced polarization) effect in the hydrogenation of acetylene dicarboxylic acid with the complex[Rh (dppb)](+) (dppb:1,4-bis(diphenylphosphino) butane)[J]. J Chem Phys, 2014, 140(9):094307.
[5] BARSKIY D A, SHCHEPIN R V, COFFEY A M, et al. Over 20% ¹⁵N Hyperpolarization in under one minute for metronidazole, an antibiotic and hypoxia probe[J]. J Am Chem Soc, 2016, 138(26):8080-8083.
[6] GLOGGLER S, GRUNFELD A M, ERTAS Y N, et al. A nanoparticle catalyst for heterogeneous phase para-hydrogen-induced polarization in water[J]. Angew Chem Int Edit, 2015, 54(8):2452-2456.
[7] WANG W Y, XU J, ZHAO Y X, et al. Facet dependent pairwise addition of hydrogen over Pd nanocrystal catalysts revealed via NMR using para-hydrogen-induced polarization[J]. Phys Chem Chem Phys, 2017, 19(14):9349-9353.
[8] KOVTUNOV K V, BECK I E, BUKHTIYAROV V I, et al. Observation of parahydrogen-induced polarization in heterogeneous hydrogenation on supported metal catalysts[J]. Angew Chem Int Edit, 2008, 47(8):1492-1495.
[9] ZHOU R H, ZHAO E W, CHENG W, et al. Parahydrogen-induced polarization by pairwise replacement catalysis on Pt and Ir nanoparticles[J]. J Am Chem Soc, 2015, 137(5):1938-1946.
[10] BARSKIY D A, COFFEY A M, NIKOLAOU P, et al. NMR hyperpolarization techniques of gases[J]. Chem Eur J, 2017, 23(4):725-751.
[11] ZHIVONITKO V V, KOVTUNOV K V, BECK I E, et al. Role of different active sites in heterogeneous alkene hydrogenation on platinum catalysts revealed by means of parahydrogen-induced polarization[J]. J Phys Chem C, 2011, 115(27):13386-13391.
[12] ZHOU R H, CHENG W, NEAL L M, et al. Parahydrogen enhanced NMR reveals correlations in selective hydrogenation of triple bonds over supported Pt catalyst[J]. Phys Chem Chem Phys, 2015, 17(39):26121-26129.
[13] SALNIKOV O G, BURUEVA D B, GERASIMOV E Y, et al. The effect of oxidative and reductive treatments of titania-supported metal catalysts on the pairwise hydrogen addition to unsaturated hydrocarbons[J]. Catal Today, 2017, 283:82-88.
[14] ZHAO E W, ZHENG H B, LUDDEN K, et al. Strong metal-support interactions enhance the pairwise selectivity of parahydrogen addition over Ir/TiO₂[J]. ACS Catal, 2016, 6(2):974-978.
[15] KOVTUNOV K V, TRUONG M L, BARSKIY D A, et al. Propane-d(6) heterogeneously hyperpolarized by parahydrogen[J]. J Phys Chem C, 2014, 118(48):28234-28243.
[16] KOPTYUG I V, KOVTUNOV K V, BURT S R, et al. Para-hydrogen-induced polarization in heterogeneous hydrogenation reactions[J]. J Am Chem Soc, 2007, 129(17):5580-5586.
[17] WANG W Y, HU H, XU J, et al. Tuning Pd-Au bimetallic catalysts for heterogeneous parahydrogen-induced polarization[J]. J Phys Chem C, 2018, 122(2):1248-1257.
[18] KOVTUNOV K V, BECK I E, ZHIVONITKO V V, et al. Heterogeneous addition of H-2 to double and triple bonds over supported Pd catalysts:a parahydrogen-induced polarization technique study[J]. Phys Chem Chem Phys, 2012, 14(31):11008-11014.
[19] BURUEVA D B, SALNIKOV O G, KOVTUNOV K V, et al. Hydrogenation of unsaturated six-membered cyclic hydrocarbons studied by the parahydrogen-induced polarization technique[J]. J Phys Chem C, 2016, 120(25):13541-13548.
[20] SALNIKOV O G, KOVTUNOV K V, BARSKIY D A, et al. Evaluation of the mechanism of heterogeneous hydrogenation of alpha, beta-unsaturated carbonyl compounds via pairwise hydrogen addition[J]. ACS Catal, 2014, 4(6):2022-2028.
[21] HORIUTI I, POLANYI M. Exchange reactions of hydrogen on metallic catalysts[J]. Trans Faraday Soc, 1934, 30:1164-1172.
[22] ZHIVONITKO V V, SKOVPIN I V, CRESPO-QUESADA M, et al. Acetylene oligomerization over Pd nanoparticles with controlled shape:a parahydrogen-induced polarization study[J]. J Phys Chem C, 2016, 120(9):4945-4953.
[23] ZHAO E W, MALIGAL-GANESH R, XIAO C, et al. Silica-encapsulated Pt-Sn intermetallic nanoparticles:a robust catalytic platform for parahydrogen-induced polarization of gases and liquids[J]. Angew Chem Int Edit, 2017, 129(14):3983-3987.
[24] BURUEVA D B, KOVTUNOV K V, BUKHTIYAROV A V, et al. Selective single-site Pd-In hydrogenation catalyst for production of enhanced magnetic resonance signals using parahydrogen[J]. Chem Eur J, 2018, 24(11):2547-2553.
[25] ZHANG H, JIN M S, XIA Y N. Enhancing the catalytic and electrocatalytic properties of Pt-based catalysts by forming bimetallic nanocrystals with Pd[J]. Chem Soc Rev, 2012, 41(24):8035-8049.
[26] SHAN S Y, PETKOV V, PRASAI B, et al. Catalytic activity of bimetallic catalysts highly sensitive to the atomic composition and phase structure at the nanoscale[J]. Nanoscale, 2015, 7(45):18936-18948.
[27] WU J F, SHAN S Y, LUO J, et al. PdCu nanoalloy electrocatalysts in oxygen reduction reaction:role of composition and phase state in catalytic synergy[J]. Acs Appl Mater Inter, 2015, 7(46):25906-25913.
[28] LOUKRAKPAM R, SHAN S Y, PETKOV V, et al. Atomic ordering enhanced electrocatalytic activity of nanoalloys for oxygen reduction reaction[J]. J Phys Chem C, 2013, 117(40):20715-20721.
[29] CASTEGNARO M V, GORGESKI A, BALKE B, et al. Charge transfer effects on the chemical reactivity of PdxCu1-x nanoalloys[J]. Nanoscale, 2016, 8(1):641-647.
[30] SHI W W, CHEN X Q, XU S Y, et al. Highly efficient PdCu3 nanocatalysts for Suzuki-Miyaura reaction[J]. Nano Res, 2016, 9(10):2912-2920.
[31] LIU J, ZHU Y N, LIU C, et al. Excellent selectivity with high conversion in the semihydrogenation of alkynes using palladium-based bimetallic catalysts[J]. Chemcatchem, 2017, 9(21):4053-4057.
[32] MARKOV P V, BRAGINA G O, BAEVA G N, et al. Pd-Cu catalysts from acetate complexes in liquid-phase diphenylacetylene hydrogenation[J]. Kinet Catal, 2015, 56(5):591-597.
[33] LIU Y A, HE Y F, ZHOU D R, et al. Catalytic performance of Pd-promoted Cu hydrotalcite-derived catalysts in partial hydrogenation of acetylene:effect of Pd-Cu alloy formation[J]. Catal Sci Technol, 2016, 6(9):3027-3037.
[34] RAVANCHI M T, SAHEBDELFAR S, KOMEILI S. Acetylene selective hydrogenation:a technical review on catalytic aspects[J]. Rev Chem Eng, 2018, 34(2):215-237.
[35] BRIDIER B, LOPEZ N, PEREZ-RAMIREZ J. Partial hydrogenation of propyne over copper-based catalysts and comparison with nickel-based analogues[J]. J Catal, 2010, 269(1):80-92.
[36] WEHRLI J T, THOMAS D J, WAINWRIGHT M S, et al. Selective hydrogenation of propyne over an ion-exchanged copper on silica catalyst[J]. Appl Catal, 1990, 66(1):199-208.
[37] BOND G C. Catalysis by metals[M]. Academic Press, 1962.
[38] JOICE B J, ROONEY J J, WELLS P B, et al. Nature and reactivity of intermediates in hydrogenation of buta-13-diene catalyzed by cobalt and palladium-gold alloys[J]. Discuss Faraday Soc, 1966, (41):223-236.
[39] RUSHFORD H G, WHAN D A. Catalytic hydrogenation of but-2-yne on palladium-gold alloys[J]. Trans Faraday Soc, 1971, 67(588):3577-3584.
[40] BOND G C, RAWLE A F. Catalytic hydrogenation in the liquid phase. Part 1. Hydrogenation of isoprene catalysed by palladium, palladium-gold and palladium-silver catalysts[J]. J Mol Cata A-Chem, 1996, 109(3):261-271.
[41] PEI G X, LIU X Y, YANG X F, et al. Performance of Cu-alloyed Pd single-atom catalyst for semihydrogenation of acetylene under simulated front-end conditions[J]. ACS Catal, 2017, 7(2):1491-1500.
[42] MCCUE A J, GIBSON A, ANDERSON J A. Palladium assisted copper/alumina catalysts for the selective hydrogenation of propyne, propadiene and propene mixed feeds[J]. Chem Eng J, 2016, 285:384-391.
[43] PRAVICA M G, WEITEKAMP D P. Net NMR alignment by adiabatic transport of parahydrogen addition products to high magnetic field[J]. Chem Phys Lett, 1988, 145(4):255-258.
[44] ZHANG J Y, FENG A N, BAI J, et al. One-pot synthesis of hierarchical flower-like Pd-Cu alloy support on graphene towards ethanol oxidation[J]. Nanoscale Res Lett, 2017, 12(1):521.
[45] BOUCHER M B, ZUGIC B, CLADARAS G, et al. Single atom alloy surface analogs in Pd_0.18Cu₁₅ nanoparticles for selective hydrogenation reactions[J]. Phys Chem Chem Phys, 2013, 15(29):12187-12196.
[46] MCCUE A J, ANDERSON J A. CO induced surface segregation as a means of improving surface composition and enhancing performance of CuPd bimetallic catalysts[J]. J Catal, 2015, 329:538-546.
[47] MCCUE A J, MCRITCHIE C J, SHEPHERD A M, et al. Cu/Al₂O₃ catalysts modified with Pd for selective acetylene hydrogenation[J]. J Catal, 2014, 319:127-135.
[48] MCCUE A J, SHEPHERD A M, ANDERSON J A. Optimisation of preparation method for Pd doped Cu/Al₂O₃ catalysts for selective acetylene hydrogenation[J]. Catal Sci Technol, 2015, 5(5):2880-2890.
[49] TIERNEY H L, BABER A E, KITCHIN J R, et al. Hydrogen dissociation and spillover on individual isolated palladium atoms[J]. Phys Rev Lett, 2009, 103(24):246102.
[50] PEI G X, LIU X Y, WANG A Q, et al. Ag alloyed Pd single-atom catalysts for efficient selective hydrogenation of acetylene to ethylene in excess ethylene[J]. ACS Catal, 2015, 5(6):3717-3725.
[51] MCCUE A J, BAKER R T, ANDERSON J A. Acetylene hydrogenation over structured Au-Pd catalysts[J]. Faraday Discuss, 2016, 188:499-523.
[52] PEI G X, LIU X Y, WANG A Q, et al. Promotional effect of Pd single atoms on Au nanoparticles supported on silica for the selective hydrogenation of acetylene in excess ethylene[J]. New J Chem, 2014, 38(5):2043-2051.
[53] TIRUVALAM R C, PRITCHARD J C, DIMITRATOS N, et al. Aberration corrected analytical electron microscopy studies of sol-immobilized Au plus Pd, Au{Pd} and Pd{Au} catalysts used for benzyl alcohol oxidation and hydrogen peroxide production[J]. Faraday Discuss, 2011, 152:63-86.
[54] GAO F, GOODMAN D W. Pd-Au bimetallic catalysts:understanding alloy effects from planar models and (supported) nanoparticles[J]. Chem Soc Rev, 2012, 41(24):8009-8020.