2002 60 3, 419 426 ACTA CHIMICA SINICA Vol 60, 2002 No 3, 419 426 Ni O Ξ Ξ ( 730000) XRD, BET, In2situ XPS O XRD, Cu2Zn O ; XRD, BET N 2 O, Ni Cu 0 Cu 0 / Ni In2situ XPS, Ni / Ni Cu +, Cu 0 / Cu +, / Ni Ni, Cu/ ZnO,,, Mechanism of O Based Catalysis for Methanol Decomposition Promoted by Nickel XI, Jing2Yu WANG, Wei2Ping LΒ, Gong2Xuan Ξ ( State Key Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000) Abstract XRD, BET and In2situ XPS techniques were used to study the performance of O based catalysts for methanol decomposition XRD studies indicated that the formation of Cu2Zn alloys was the major reason for the quickly deactivation of catalyst for methanol decomposition at the initial stage of the reaction XRD, BET and N 2 O titration results confirmed that nickel additive could increase the dispersity of active Cu 0 species during the catalytic process and maintain the stability during the reaction In2situ XPS studies confirmed that the active center in / Ni catalyst was Cu 0 and/ or Cu + species, in which Cu + was formed during the reaction Keywords Ni, O based methanol decomposition catalysts, H 2, promotion effect, catalytic characterization,, 200,, [3 6 Cu ],, [7,8 [1 ] Pd ] Cu, [2 ] O [3,4 ] Cu/ Cr [5,6 ] 200 500, O, Ξ E2mail : gxlu @ns lzb ac cn Received June 29, 2001 ; revised October 8, 2001 ; accepted December 17, 2001 (No G20000264)
420 Vol 60, 2002 [1 ] ; N 2 O + 2Cu(s) Cu 2 O + N 2 Cu/ Cr, Cu Altamira [6 ] AMI2100 200 mg 4 mm U [9 11, ], 10 % H 2 (He, 50 ml/ min) 180, 300 30 min, 230 30 min,, 50 ml/ min H 2 30 min,, 230, 60 ml/ min 30 min, O 40 N 2 O,,, 200 L, ( Ametek Instruments, Dycor O, Ni system 1000) N 2 N 2 O [12 ], / Ni In2situ XPS VG ESCALAB 210 Mg K (1253 6 ev) Ni,, C 1S = 285 00 ev XRD, BET, N 2 O Cu 0, In2situ XPS,, O Ni,,, CH 3 OH,,,, 1 1 1 Cu (NO 3 ) 2 3H 2 O, Zn (NO 3 ) 2 6H 2 O, Ni (NO 3 ) 2, 6H 2 O, Na 2 CO 3,, 1 3 Cu ( ) Cu, Zn, Ni, 4 mm, 400 mg V ( H 2 ) V Na 2 CO 3, (N 2 ) = 10 90, 300 2 h,, 2 h, ph 20 ml/ min, 7 0 110 10 h, 400, CH 3 OH 3 h 13X 40 60 (0 2 0 45 mm) 1 2 Rigaku D/ MAX2RB X, Cu K, 50 2 kv, 80 ma,2 10 80, 2 1 XRD : N 2 BET Cu,, Micromeritics ASAP2010 Cu 0[1 ],, N 2 O [13 Cu ], : CH 3 OH,,, 50, 100, 150, 200 250, XPS Porapak Q 1 H 2, CH 3 OH, CO
No 3 : Ni O 421 (5/ 5) CuO, / Ni (5/ 4/ 1) XRD, ; ZnO H 2 CH 3 OH, 2 43 3 50 4 Cu 0, ZnO Ni ; CO CuO, 2 42 6 49 6 Cu2Zn Cu 0, Cu 0,, CuO Cu 2 O ( N 2 O Cu 0 Zn 0, XRD, 2 2 ) (5/ 5), Cu 2 + (CuO) Cu 0 ; ZnO CO > H 2 CH 3 OH, H 2 CH 3 OH ZnO Zn 0, CuO Cu 0 ZnO ; CO, ZnO, ZnO O, ZnO Zn Cu Cu2Zn ( Cu2Zn ) 2 XRD Figure 2 XRD patterns of unreduced (5/ 5) (a) and Cu/ Zn/ Ni (5/ 4/ 1) (b) catalysts ( g ) ZnO ; ( ) CuO 1 (5/ 5) XRD Figure 1 XRD patterns of (5/ 5) catalysts reduced by different reducing agents : H 2 (a), CH 3 OH (b) and CO (c) ( g ) ZnO ; ( ) Cu ; ( ) Cu2Zn Alloy 2 (5/ 5) / Ni 3 10 % H 2 (N 2 ) 300 2 h (5/ 5) / Ni (5/ 4/ 1) XRD 2 43 3 50 4 Cu 0, ZnO ;, CuO Cu 2 O Zn 0, (5/ 5) / Ni (5/ 4/ 1) Cu 2 + (CuO) Cu 0 ; ZnO, H 2 4 250 20 h (5/ 5) / Ni (5/ 4/ 1) XRD (5/ 5) (5/ 4/ 1) XRD 2, ZnO Cu 0, 2 42 3 CuO, ZnO 49 3 Cu2Zn, / Ni (5/ 4/ 1) 2 38 7 (5/ 5) CuO (5/ 5) Cu2Zn, Cheng [3 ] CuO, / Ni (5/ 4/ 1) (5/ 5), 2 35 4 XRD XRD
422 Vol 60, 2002 ( 3), Cu2Zn ZnO, / Ni (5/ 4/ 1) CO, Cu2Zn,, Cu 0 / Ni 3 XRD Figure 3 XRD patterns of reduced (5/ 5) (a) and / Ni (5/ 4/ 1) (b) catalysts ( g ) ZnO ; ( ) CuO 4 250 20 h XRD Figure 4 XRD patterns of (5/ 5) (a) and / Ni (5/ 4/ 1) (b) catalysts used for 20 h at 250 ( g ) ZnO ; ( ) Cu ; ( ) Cu2Zn Alloy (5/ 4/ 1) / Ni (5/ 4/ 1) (, ) XRD Ni, Ni NiO x,xrd,, Cu, XPS ( ) 2 2 BET Cu 0 Ni Cu, BET N 2 O Cu 0, 1, / Ni (5/ 4/ 1) BET (5/ 5), Cu/ Zn/ Ni (5/ 4/ 1) Cu 0 (5/ 5) 20 % Cu 0 / Ni (5/ 4/ 1) ( Cu 0 Cu 0 BET ) 46 4 %, (5/ 5) 32 5 % Ni Cu 0, XRD 2 3 In2situ XPS 5 (5/ 5) Cu 2p XPS, Cu Lv1 XPS, Zn 2p XPS, 2 Cu/ Zn (5/ 5) XPS 6 Cu/ Zn/ Ni (5/ 4/ 1) Cu 2p XPS, Cu Lv1 XPS, Zn 2p XPS, Ni 2p XPS, 3 / Ni ( 5/ 4/ 1) XPS XPS 1 BET Cu 0 Table 1 The composition, BET surface area and copper surface area of the catalysts Catalyst Weight ratio of the metal BET surface area (m 2 / g Cat ) Copper surface area (m 2 / g Cat ) Copper dispersity in surface ( %) D Cu (nm) (5/ 5) / Ni (5/ 4/ 1) 5 5 31 7 10 3 32 5 25 97 5 4 1 26 7 12 4 46 4 21 61
No 3 : Ni O 423, Cu, Cu 2p XPS [14, ], 250, 2 5 : Cu/, Zn (5/ 5) Cu 2p 3/ 2 932 81 Cu Cu 2 + Cu + Cu 0, CuO ev, Cu 1850 48 ev, Cu Cu 0, Cu 2p XPS (5/ 5) Cu Lv1, CuO Cu 2p Cu 0,, XPS, CuO, Cu Cu Cu, Cu 0,, Cu 2p 3/ 2, Cu XPS 5 (5/ 5) XPS Figure 5 XPS spectra for (5/ 5) catalyst at room temperture (a), 50 (b), 100 (c), 150 (d), 200 (e) and 250 (f) 2 (5/ 5) XPS (ev) Table 2 XPS analyses of (5/ 5) catalyst (ev) r t 50 100 150 200 250 Cu 2p 3/ 2 932 81 932 77 932 75 932 65 932 33 932 36 Cu 2p 1/ 2 952 73 952 69 952 51 952 49 952 17 952 12 Cu Lv1 335 93 336 13 336 19 336 25 336 17 336 20 Zn 2p 3/ 2 1021 33 1021 53 1021 51 1021 49 1020 93 1020 64 Zn 2p 1/ 2 1044 45 1044 65 1044 63 1044 61 1043 97 1043 76 Zn LM1 264 28 264 34 264 28 264 46 263 86 263 43 O 1s 530 52 530 76 530 64 530 58 529 92 529 39
424 Vol 60, 2002 2 5 : Jung [15 ] Zn 0 Cu 0, (5/ 5) Zn 2p 3/ 2 Cu2Zn,, 1021 33 ev, Zn + 2, Zn Cu ZnO ; Cu2Zn XRD, Zn 2p 3/ 2, (5/ 5) Cu2Zn 150,, 150, 1021149 ev 250 1020 64 ev, Zn 2 +, Zn 0, Cu2Zn,CH 3 OH : H 2 CO, XRD CH 3 OH (ads) 2H 2 (ads) + CO (ads), H 2 CH 3 OH ZnO, CO(ads) + ZnO CO 2 (ads) + Zn ZnO CO, CO 2 (ads) CO 2 (g) CO 2, Zn + Cu CuZn (Alloy), CO 2 6 (5/ 4/ 1) XPS Figure 6 XPS spectra for (5/ 4/ 1) catalyst at room temperture (a), 50 (b), 100 (c), 150 (d), 200 (e) and 250 (f) 3 / Ni (5/ 4/ 1) XPS (ev) Table 3 XPS analyses of / Ni (5/ 4/ 1) catalyst (ev) r t 50 100 150 200 250 Cu 2p 3/ 2 932 65 932 41 932 27 931 47 932 29 932 39 Cu 2p 1/ 2 952 57 952 33 952 19 951 39 952 13 952 23 Cu Lv1 335 41 335 25 334 95 334 91 334 93 335 03 Zn 2p 3/ 2 1021 61 1021 37 1021 07 1021 27 1021 37 1021 63 Zn 2p 1/ 2 1044 65 1044 41 1044 19 1044 31 1044 41 1044 75 Zn LM1 264 66 264 36 264 06 263 54 264 28 264 58 Ni 2p 3/ 2 855 25 855 09 855 19 855 07 854 93 855 27 Ni 2p 1/ 2 872 77 872 69 872 95 872 51 872 53 873 19 O 1s 530 78 530 66 530 72 530 72 530 36 530 36
No 3 : Ni O 425 3 6 : / Ni (5/ 4/ 1) Cu 2p 3/ 2, Cu 0 932 65 ev,cu 1850 84 ev,, Cu Cu 0, Cu 2p XPS, CuO Cu Ni, Cu2Zn 2p XPS,, Ni Zn CuO, Cu 2p 3/ 2 Cu 2p, ZnO, XPS (5/ 5) Cu +, XPS, (5/ 5) O Cu Cu (5/ 5),, Cu/ 36 7 % ; / Ni (5/ 4/ 1) O Zn/ Ni (5/ 4/ 1) Cu Lv1 44 5 %, 250 35 7 % Cu/, 150 Cu Zn (5/ 5) O Lv1, ( ) / Ni (5/ 4/ 1), Cu +, ( ) Cu 0, (5/ 5) O I + Cu / I Cu0 250, Cu + Cu 0 ZnO 2 4 / Ni Ni (5/ 4/ 1) Cu + [12, O ] XPS Cu + XRD,, / Ni (5/ 4/ 1) Cu 0 Cu + Cu/ CO Zn/ Ni (5/ 4/ 1), (5/ 5) Cu 0 / Cu + ZnO Cu2Zn, 3 6 : / Cu 0, Ni (5/ 4/ 1) Zn 2p 3/ 2, 250 1021 61 ev, Zn + 2, Zn / Ni (5/ 4/ 1) (5/ 5), Cu2Zn, ZnO ;, Zn 2p 3/ 2 Cu Cu 0,, / Ni (5/ 4/ 1) ZnO, Cu2Zn,, / Ni (5/ 4/ 1) XRD, 19 2 % ; H 2 3 6 : Cu/ / Ni (5/ 4/ 1), Zn/ Ni (5/ 4/ 1) Ni 2p 3/ 2,Ni CuO 855 25 ev, Ni 2p 1/ 2 872 77 ev,, 17 52 ev, Ni 0, Ni 2p XPS Cu 0, / Ni (5/ 4/ 1), NiO Ni 2p XPS Cn/ Zn Cu2Zn ;, Cn/ Zn/ 50 3 %, 250, 4 3 5 % ; H 2 33 1 % ; 20 h (5/ 5) Cu 0,, 77 3 % ;, Ni / Ni (5/ 20 h / Ni 4/ 1), Cu2Zn, Ni 0, NiO,, 67 3 % [12, ] Cu2Zn, Ni 2p 3/ 2 Ni 2p 1/ 2, Ni 2p XPS, Ni Cu 0, Ni Cu 0
426 Vol 60, 2002 / Ni ;, Ni / Ni Cu +, Cu 0 / Cu + 6 Cheng, W H ; Shiau, C Y ; Liu, T H ; Tung, H L ;, / Ni Y ; Haruta, H Appl Catal A 1998, 171, 123 4 8 Matsumura, Y ; Okumura, M ; Usami, Y ; Kagawa, K ; Table 4 Methanol conversions over different catalysts Yamashita, H ; Anpo, M ; Havata, M Catal Lett Catalyst (CO reduced, fresh) (H 2 reduced, fresh) (H 2 reduced, used) / Ni (H 2 reduced, fresh) / Ni (H 2 reduced, used) a - No peak ; + Strong peak References Diffraction peak a CuO ZnO Cu Cu2Zn Conversion ( %) b - + - + 3 5 - + + - 33 1 - + + + 19 2 - + + - 77 3 - + + - 67 3 b T = 250, LHSV = 2 0 h - 1 1 Cheng, W H Acc Chem Res 1999, 32, 685 2 Pena, M A ; Gomez, J P ; Fierro, J L G Appl Catal A 1996, 144, 7 3 Cheng, W H Appl Catal A 1995, 130, 13 4 Cheng, W H Mater Chem Phys 1995, 41, 36 5 Cheng, W H Appl Catal B 1995, 7, 127 Lu, J F ; Hsu, C C Appl Catal A 1998, 170, 215 7 Yoshikazu, U ; Kenkichi, K ; Masanobu, K ; Sakurai, 1997, 44, 189 9 Matsumura, Y ; Tanaka, K ; Tode, N ; Yaxawa, T ; Haruta, M J Mol Catal A 2000, 152, 157 10 Liu, Y Y ; Suzuki, K ; Hamakawa, S ; Hayakawa, T ; Murata, K ; Ishii, T ; Kumagai, M Catal Lett 2000, 66, 205 11 Shen, W J ; Matsumura, Y J Mol Catal A 2000, 153, 165 12 Xi, J 2Y ; Lu, G 2X Chin J Mol Catal 2001, 15 (3), 191 (in Chinese) (,,, 2001, 15 (3), 191 ) 13 Marino, F J ; Cerrella, E G ; Duhalde, S ; Jobbagy, M ; Laborde, M A Int J Hydrogen Energy 1998, 23, 1095 14 WU, N2Z Petrochem Tech 1990, 23, 1095 ( in Chinese) (,, 1990, 23, 1095 ) 15 Jung, K D ; Joo, O S ; Han, S H Catal Lett 2000, 68, 49 (A0106299 PAN, B F ; HUANG, W Q )
March 2002 Graphical Abstract Mechanism of O Based Catalysis for Methanol Decomposition Promoted by Nickel XI, Jing2Yu ; WANG, Wei2Ping ; LΒ, Xuan Acta Chimica Sinica 2002, 60 (3), 419 Gong2 In2situ XPS studies confirmed that the active center in / Ni catalyst was Cu 0 and/ or Cu + species, in which Cu + was formed during the reaction, and led to the high activity of Cu/ Zn/ Ni catalyst The Cathodic Reduction Process of the Anodic Pb( ) Oxides Film Formed on Lead LIU, Hou2Tian ; LIANG, Hai2He ; YANG, Jiong ; YANG, Chun2Xiao ; ZHOU, Wei2 Fang Acta Chimica Sinica 2002, 60 (3), 427 The fractions of the Pb ( ) oxides, PbO and PbO PbSO 4 in the anodic films formed on Pb unreduced at the potentials marked by black dots were measured using linear sweep voltammogram The results show that the surface layer of the PbO particles is reduced to the metal Pb, at first, and then the PbO and PbO PbSO 4 particles are reduced together, when the metal Pb in the surface layer of the PbO particles meets the PbO PbSO 4 particles, and the reduction of PbO PbSO 4 particles is slightly faster than that of the PbO particles Theoretical Study of the Gas Phase Reaction of CH 3 S with O 2 WANG, Shao2Kun ; ZHANG, Qing2Zhu ; CAO, Cheng2Bo ; GU, Yue2Shu Acta Chimica Sinica 2002, 60 (3), 432 Theoretical Studies on the Structure of Hydrogen2Bonding Clathrate of [ ( C 2 H 5 ) 4 N + 2 Cl - 2( NH 2 ) 2 CO] LI, Qi ; HU, Xiang2Li ; MA, Si2Yu ; LIU, Ruo2 Zhuang Acta Chimica Sinica 2002, 60 (3), 438 The semi2empirical AM1 MO method is used to calculate the structure of a typi2 cal hydrogen2bonding clathrate urea tetraethylammonium chloride complexes [ (C 2 H 5 ) 4 N + Cl - 2 (NH 2 ) 2 CO ], and the weak intermolecular interaction in the self2assembled process is analyzed