ACTA CHIMICA SINICA. Cu/ ZnO ; XRD, BET N 2 O. . In2situ XPS, Ni Cu/ Zn/ Ni. . Ni, Cu/ ZnO

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1 , ACTA CHIMICA SINICA Vol 60, 2002 No 3, Ni O Ξ Ξ ( ) 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 ) 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 ] , O, Ξ E2mail : lzb ac cn Received June 29, 2001 ; revised October 8, 2001 ; accepted December 17, 2001 (No G )

2 420 Vol 60, 2002 [1 ] ; N 2 O + 2Cu(s) Cu 2 O + N 2 Cu/ Cr, Cu Altamira [6 ] AMI mg 4 mm U [9 11, ], 10 % H 2 (He, 50 ml/ min) 180, min, 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 ( ev) Ni,, C 1S = ev XRD, BET, N 2 O Cu 0, In2situ XPS,, O Ni,,, CH 3 OH,,,, 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, h,, 2 h, ph 20 ml/ min, h, 400, CH 3 OH 3 h 13X ( mm) 1 2 Rigaku D/ MAX2RB X, Cu K, 50 2 kv, 80 ma, , 2 1 XRD : N 2 BET Cu,, Micromeritics ASAP2010 Cu 0[1 ],, N 2 O [13 Cu ], : CH 3 OH,,, 50, 100, 150, , XPS Porapak Q 1 H 2, CH 3 OH, CO

3 No 3 : Ni O 421 (5/ 5) CuO, / Ni (5/ 4/ 1) XRD, ; ZnO H 2 CH 3 OH, Cu 0, ZnO Ni ; CO CuO, 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 ) h (5/ 5) / Ni (5/ 4/ 1) XRD Cu 0, ZnO ;, CuO Cu 2 O Zn 0, (5/ 5) / Ni (5/ 4/ 1) Cu 2 + (CuO) Cu 0 ; ZnO, H h (5/ 5) / Ni (5/ 4/ 1) XRD (5/ 5) (5/ 4/ 1) XRD 2, ZnO Cu 0, CuO, ZnO 49 3 Cu2Zn, / Ni (5/ 4/ 1) (5/ 5) CuO (5/ 5) Cu2Zn, Cheng [3 ] CuO, / Ni (5/ 4/ 1) (5/ 5), XRD XRD

4 422 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 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 No 3 : Ni O 423, Cu, Cu 2p XPS [14, ], 250, 2 5 : Cu/, Zn (5/ 5) Cu 2p 3/ Cu Cu 2 + Cu + Cu 0, CuO ev, Cu 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 Cu 2p 3/ Cu 2p 1/ Cu Lv Zn 2p 3/ Zn 2p 1/ Zn LM O 1s

6 424 Vol 60, : Jung [15 ] Zn 0 Cu 0, (5/ 5) Zn 2p 3/ 2 Cu2Zn,, ev, Zn + 2, Zn Cu ZnO ; Cu2Zn XRD, Zn 2p 3/ 2, (5/ 5) Cu2Zn 150,, 150, ev 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 Cu 2p 3/ Cu 2p 1/ Cu Lv Zn 2p 3/ Zn 2p 1/ Zn LM Ni 2p 3/ Ni 2p 1/ O 1s

7 No 3 : Ni O : / Ni (5/ 4/ 1) Cu 2p 3/ 2, Cu ev,cu 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 Lv %, % 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, 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 : Cu/ / Ni (5/ 4/ 1), Zn/ Ni (5/ 4/ 1) Ni 2p 3/ 2,Ni CuO ev, Ni 2p 1/ ev,, ev, Ni 0, Ni 2p XPS Cu 0, / Ni (5/ 4/ 1), NiO Ni 2p XPS Cn/ Zn Cu2Zn ;, Cn/ Zn/ 50 3 %, 250, % ; H % ; 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

8 426 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, 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 b T = 250, LHSV = 2 0 h Cheng, W H Acc Chem Res 1999, 32, 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, Yoshikazu, U ; Kenkichi, K ; Masanobu, K ; Sakurai, 1997, 44, Matsumura, Y ; Tanaka, K ; Tode, N ; Yaxawa, T ; Haruta, M J Mol Catal A 2000, 152, Liu, Y Y ; Suzuki, K ; Hamakawa, S ; Hayakawa, T ; Murata, K ; Ishii, T ; Kumagai, M Catal Lett 2000, 66, Shen, W J ; Matsumura, Y J Mol Catal A 2000, 153, 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, 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 (A PAN, B F ; HUANG, W Q )

9 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