您的位置:山东大学 -> 科技期刊社 -> 《山东大学学报(理学版)》

《山东大学学报(理学版)》 ›› 2018, Vol. 53 ›› Issue (11): 9-17.doi: 10.6040/j.issn.1671-9352.0.2018.345

•   • 上一篇    下一篇

分级多孔金-铜薄膜对苯甲醇的催化氧化

何淑仁(),唐斌,邢新峰,石春颖,张秀梅,张晓梅,许效红*()   

  1. 山东大学化学与化工学院,山东 济南 250100
  • 收稿日期:2018-06-14 出版日期:2018-11-01 发布日期:2018-11-14
  • 通讯作者: 许效红 E-mail:15154125052@163.com;xhxu@sdu.edu.cn
  • 作者简介:何淑仁(1990—),男,硕士研究生,研究方向为纳米催化. E-mail:15154125052@163.com
  • 基金资助:
    国家自然科学基金资助项目(21176144);国家自然科学基金资助项目(21472117)

Hierarchically porous Au-Cu thin films as catalysts for aerobic oxidation of benzyl alcohol

Shu-ren HE(),Bin TANG,Xin-feng XING,Chun-ying SHI,Xiu-mei ZHANG,Xiao-mei ZHANG,Xiao-hong XU*()   

  1. School of Chemical and Chemical Engineering, Shandong University, Jinan 250100, Shandong, China
  • Received:2018-06-14 Online:2018-11-01 Published:2018-11-14
  • Contact: Xiao-hong XU E-mail:15154125052@163.com;xhxu@sdu.edu.cn
  • Supported by:
    国家自然科学基金资助项目(21176144);国家自然科学基金资助项目(21472117)

摘要:

采用合金/去合金法,在金-铜合金线表面制备了分级多孔金-铜薄膜结构(Hierarchically porous Au-Cu thin films,HPAFs)。该分级多孔结构是由微米级的大尺寸孔道-系带和纳米级小尺寸系带-孔道构成。通过对电沉积、退火处理及腐蚀条件的控制可以调控表面多孔薄膜层的厚度、结构以及组成。研究结果表明,脱合金处理残留的铜在富金的系带上形成了金主导的AuCu合金-CuOx异质结构,其可以有效地促进分子氧的活化,而分级多孔结构有利于反应物分子在孔内的扩散传质,从而赋予HPAFs催化剂对苯甲醇分子氧氧化反应高催化活性。

关键词: 表面分级多孔结构, 合金/去合金, Au-Cu, 苯甲醇, 催化氧化

Abstract:

Hierarchically porous Au-Cu thin films (HPAFs) fabricated on Au-Cu alloy wire surface by an alloying/dealloying process are reported, which exhibit superior catalytic performance for benzyl alcohol aerobic oxidation. The porous structure is composed of large-sized ligament channels (several micrometers) coupled with small-sized ligament pores (tens of nanometers), which interpenetrate in the big architecture. The morphology and composition of HPAFs can be easily tailored by altering electrodeposition, pretreatment and corrosion conditions. The characterization reveals that Cu residue in Au-rich ligament created an Au dominated AuCu(alloy)-CuOx heterostruture, which is highly active for molecular oxygen activation and favorable for benzyl alcohol aerobic oxidation. Furthermore, the surface thin-layer hierarchically porous structure of HPAFs enables the decrease in the internal diffusion resistance, and therefore further improves their catalytic performance where the pore diffusion is the rate-limiting step.

Key words: surface hierarchical porous structure, alloying/dealloying, Au-Cu, synergistic catalytic effect, benzyl alcohol aerobic oxidation

中图分类号: 

  • O643.3

图1

HPAFs制备流程图"

图2

HPAFs样品的扫描电镜(SEM)图 a,低放大倍数的HPAFs-9 h的SEM图;b, HPAFs-9 h的SEM截面图;c, HPAFs-1/6 h;d, HPAFs-1 h;e, HPAFs-9 h;f, HPAFs-24 h。"

图3

不同处理阶段样品的X射线粉末衍射(XRD)图 a,原始AuCu合金线;b,电沉积Cu并退火后的AuCu合金线;c,HPAFs-9 h。"

表1

XPS测试分析得到的HPAFs表面的Au/Cu原子比"

HPAFs催化剂 HPAFs-1/6 h HPAFs-1 h HPAFs-9 h HPAFs-24 h
Au/Cu原子比 92:8 94:6 95:5

图4

Au 4f在HPAFs- 1/6 h、1 h、9 h和24 h中的XPS图谱"

图5

Cu 2p在HPAFs-1/6 h(a)、HPAFs-1 h(b)、HPAFs-9 h(c)和HPAFs-24 h(d)中的XPS图谱"

图6

HPAFs样品的电化学性能表征 a,原始合金线; b, c,HPAFs-9 h样品开始扫描及达到稳态后; d, e,HPAFs-24 h样品开始扫描及稳定后的在N2吹扫的0.5 mol/L H2SO4溶液中的C-V扫描曲线。扫描速率为20 mV/s。"

图7

HPAFs对苯甲醇氧化的催化性能曲线(反应条件:反应温度280 ℃,氧醇比1.05,总气体流量44 mL/min,苯甲醇进样浓度0.36 mmol/min,催化剂用量20 mg。实心符号为苯甲醇的转化率,空心符号为苯甲醛的选择性)"

图8

HPAFs-9 h样品在280 ℃下反应7 h后的SEM图"

图9

氧气浓度对HPAFs-9 h催化氧化苯甲醇活性的影响(反应温度240 ℃,催化剂用量20 mg,总气体流量44 mL/min,苯甲醇进样浓度0.36 mmol/min)"

图10

苯甲醇进样浓度对HPAFs-9 h催化苯甲醇氧化反应活性的影响(反应条件:氧气体积分数10%,反应温度240 ℃,催化剂用量10 mg)"

1 XU C X , SU J X , XU X H , et al. Low temperature CO oxidation over unsupported nanoporous gold[J]. J Am Chem Soc, 2007, 129 (1): 42- 43.
doi: 10.1021/ja0675503
2 ZIELASEK V , JVRGENS B , SCHULZ C , et al. Gold catalysts: nanoporous gold foams[J]. Angew Chem Int Ed, 2006, 45 (48): 8241- 8244.
doi: 10.1002/(ISSN)1521-3773
3 WITTSTOCK A , ZIELASEK V , BIENER J , et al. Nanoporous gold catalysts for selective gas-phase oxidative coupling of methanol at low temperature[J]. Science, 2010, 327 (5963): 319- 322.
doi: 10.1126/science.1183591
4 LI Z W , XU J L , GU X H , et al. Selective gas-phase oxidation of alcohols over nanoporous silver[J]. Chem Cat Chem, 2013, 5 (7): 1705- 1708.
5 HE L , HUANG Y , WANG A , et al. H2 production by selective decomposition of hydrous hydrazine over Raney Ni catalyst under ambient conditions[J]. AIChE J, 2013, 59 (11): 4297- 4302.
doi: 10.1002/aic.v59.11
6 ZHANG J , LIU P , MA H , et al. Nanostructured porous gold for methanol electro-oxidation[J]. J Phys Chem C, 2007, 111 (28): 10382- 10388.
doi: 10.1021/jp072333p
7 ZEIS R , MATHUR A , FRITZ G , et al. Platinum-plated nanoporous gold: an efficient, low Pt loading electrocatalyst for PEM fuel cells[J]. J Power Sources, 2007, 165 (1): 65- 72.
8 CHEN L Y , CHEN N , HOU Y , et al. Geometrically controlled nanoporous PdAu bimetallic catalysts with tunable Pd/Au ratio for direct ethanol fuel cells[J]. ACS Catal, 2013, 3 (6): 1220- 1230.
doi: 10.1021/cs400135k
9 GE X , CHEN L , KANG J , et al. A core-shell nanoporous Pt-Cu catalyst with tunable composition and high catalytic activity[J]. Adv Funct Mater, 2013, 23 (33): 4156- 4162.
doi: 10.1002/adfm.v23.33
10 WITTSTOCK A , NEUMANN B , SCHAEFER A , et al. Nanoporous Au: an unsupported pure gold catalyst?[J]. J Phys Chem C, 2009, 113 (14): 5593- 5600.
doi: 10.1021/jp808185v
11 YIN H M , ZHOU C Q , XU C X , et al. Aerobic oxidation of d-glucose on support-free nanoporous gold[J]. J Phys Chem C, 2008, 112 (26): 9673- 9678.
doi: 10.1021/jp8019864
12 HAN D Q , XU T T , SU J X , et al. Gas-phase selective oxidation of benzyl alcohol to benzaldehyde with molecular oxygen over unsupported nanoporous gold[J]. Chem Cat Chem, 2010, 2 (4): 383- 386.
13 WANG D S , LI Y D . Bimetallic nanocrystals: liquid-phase synthesis and catalytic applications[J]. Adv Mater, 2011, 23 (9): 1044- 1060.
doi: 10.1002/adma.201003695
14 JIANG H L , XU Q . Recent progress in synergistic catalysis over heterometallic nanoparticles[J]. J Mater Chem, 2011, 21 (36): 13705- 13725.
doi: 10.1039/c1jm12020d
15 SANKAR M , DIMITRATOS N , MIEDZIAK P J , et al. Designing bimetallic catalysts for a green and sustainable future[J]. Chem Soc Rev, 2012, 41 (24): 8099- 8139.
doi: 10.1039/c2cs35296f
16 YUAN Z Y , SU B L . Insights into hierarchically meso-macroporous structured materials[J]. J Mater Chem, 2006, 16 (7): 663- 677.
doi: 10.1039/B512304F
17 CHEN L H , LI X Y , ROOKE J C , et al. Hierarchically structured zeolites: synthesis, mass transport properties and applications[J]. J Mater Chem, 2012, 22 (34): 17381- 17403.
doi: 10.1039/c2jm31957h
18 ZHOU Z , ZENG T , CHENG Z , et al. Diffusion-enhanced hierarchically macro-mesoporous catalyst for selective hydrogenation of pyrolysis gasoline[J]. AIChE J, 2011, 57 (8): 2198- 2206.
doi: 10.1002/aic.v57.8
19 DING Y , ERLEBACHER J . Nanoporous metals with controlled multimodal pore size distribution[J]. J Am Chem Soc, 2003, 125 (26): 7772- 7773.
doi: 10.1021/ja035318g
20 DU M , ZHANG H , LI Y , et al. Fabrication and wettability of monolithic bimodal porous Cu with Gasar macro-pores and dealloying nano-pores[J]. Appl Surf Sci, 2015, 353: 804- 810.
doi: 10.1016/j.apsusc.2015.07.020
21 DU M , ZHANG H , LI Y , et al. Synthesis of a bimodal porous Cu with nanopores on the inner surface of Gasar pores: Influences of preparation conditions[J]. Appl Surf Sci, 2016, 360: 148- 156.
doi: 10.1016/j.apsusc.2015.11.033
22 BRACEY C L , ELLIS P R , HUTCHINGS G J . Application of copper-gold alloys in catalysis: current status and future perspectives[J]. Chem Soc Rev, 2009, 38 (8): 2231- 2243.
doi: 10.1039/b817729p
23 WANG A Q , LIU X Y , MOU C Y , et al. Understanding the synergistic effects of gold bimetallic catalysts[J]. J Catal, 2013, 308: 258- 271.
doi: 10.1016/j.jcat.2013.08.023
24 PINA C D , FALLETTA E , ROSSI M . Highly selective oxidation of benzyl alcohol to benzaldehyde catalyzed by bimetallic gold-copper catalyst[J]. J Catal, 2008, 260: 384- 386.
doi: 10.1016/j.jcat.2008.10.003
25 LI W J , WANG A Q , LIU X Y , et al. Silica-supported Au-Cu alloy nanoparticles as an efficient catalyst for selective oxidation of alcohols[J]. Appl Catal A, 2012, 433/434: 146- 151.
doi: 10.1016/j.apcata.2012.05.014
26 BAUER J C , VEITH G M , ALLARD L F , et al. Silica-supported Au-CuOx hybrid nanocrystals as active and selective catalysts for the formation of acetaldehyde from the oxidation of ethanol[J]. ACS Catal, 2012, 2 (12): 2537- 2546.
doi: 10.1021/cs300551r
27 BELIN S , BRACEY C L , BRIOIS V , et al. CuAu/SiO2 catalysts for the selective oxidation of propene to acrolein: the impact of catalyst preparation variables on material structure and catalytic performance[J]. Catal Sci Technol, 2013, 3 (11): 2944- 2957.
doi: 10.1039/c3cy00254c
28 ZHAO G , HU H , DENG M , et al. Au/Cu-fiber catalyst with enhanced low-temperature activity and heat transfer for the gas-phase oxidation of alcohols[J]. Green Chem, 2011, 13 (1): 55- 58.
doi: 10.1039/C0GC00679C
29 JIA Q Q , ZHAO D F , TANG B , et al. Synergistic catalysis of Au-Cu/TiO2-NB nanopaper in aerobic oxidation of benzyl alcohol[J]. J Mater Chem A, 2014, 2 (38): 16292- 16298.
doi: 10.1039/C4TA01503G
30 XING X F , HAN D Q , WU Y F , et al. Fabrication and electrochemical property of hierarchically porous Au-Cu films[J]. Mater Lett, 2012, 71: 108- 110.
doi: 10.1016/j.matlet.2011.12.056
31 WAGNER C D , RIGGS W M , DAVIS L E , et al. Handbook of X-ray photoelectron spectroscopy[M]. Minnesota: Perkin-Elmer Corporation, 1979: 82- 83.
32 ZELEKEW O A , KUO D H . Facile synthesis of SiO2@ CuxO@ TiO2 heterostructures for catalytic reductions of 4-nitrophenol and 2-nitroaniline organic pollutants[J]. Appl Surf Sci, 2017, 393: 110- 118.
doi: 10.1016/j.apsusc.2016.10.016
33 FUJITA T , GUAN P , MCKENNA K , et al. Atomic origins of the high catalytic activity of nanoporous gold[J]. Nat Mater, 2012, 11 (9): 775- 780.
doi: 10.1038/nmat3391
34 FOGLER H S . Elements of chemical reaction engineering[M]. 4th ed New Jersey: Pearson Education Inc, 2006: 839.
35 KIM D H , LIM M S . Kinetics of selective CO oxidation in hydrogen-rich mixtures on Pt/alumina catalysts[J]. Appl Catal A, 2002, 224 (1/2): 27- 38.
36 CONTE M , MIYAMURA H , KOBAYASHI S , et al. Spin trapping of Au-H intermediate in the alcohol oxidation by supported and unsupported gold catalysts[J]. J Am Chem Soc, 2009, 131 (20): 7189- 7196.
doi: 10.1021/ja809883c
[1] 潘金鼎,李佳琪,冯艳,陈运法,杨军. 负载型钌基纳米结构用于挥发性有机化合物催化氧化的研究[J]. 山东大学学报(理学版), 2017, 52(5): 18-24.
Viewed
Full text


Abstract

Cited

  Shared   
  Discussed   
[1] 杨军. 金属基纳米材料表征和纳米结构调控[J]. 山东大学学报(理学版), 2013, 48(1): 1 -22 .
[2] 何海伦, 陈秀兰*. 变性剂和缓冲系统对适冷蛋白酶MCP-01和中温蛋白酶BP-01构象影响的圆二色光谱分析何海伦, 陈秀兰*[J]. 山东大学学报(理学版), 2013, 48(1): 23 -29 .
[3] 赵君1,赵晶2,樊廷俊1*,袁文鹏1,3,张铮1,丛日山1. 水溶性海星皂苷的分离纯化及其抗肿瘤活性研究[J]. J4, 2013, 48(1): 30 -35 .
[4] 孙小婷1,靳岚2*. DOSY在寡糖混合物分析中的应用[J]. J4, 2013, 48(1): 43 -45 .
[5] 罗斯特,卢丽倩,崔若飞,周伟伟,李增勇*. Monte-Carlo仿真酒精特征波长光子在皮肤中的传输规律及光纤探头设计[J]. J4, 2013, 48(1): 46 -50 .
[6] 杨伦,徐正刚,王慧*,陈其美,陈伟,胡艳霞,石元,祝洪磊,曾勇庆*. RNA干扰沉默PID1基因在C2C12细胞中表达的研究[J]. J4, 2013, 48(1): 36 -42 .
[7] 冒爱琴1, 2, 杨明君2, 3, 俞海云2, 张品1, 潘仁明1*. 五氟乙烷灭火剂高温热解机理研究[J]. J4, 2013, 48(1): 51 -55 .
[8] 杨莹,江龙*,索新丽. 容度空间上保费泛函的Choquet积分表示及相关性质[J]. J4, 2013, 48(1): 78 -82 .
[9] 李永明1, 丁立旺2. PA误差下半参数回归模型估计的r-阶矩相合[J]. J4, 2013, 48(1): 83 -88 .
[10] 杨永伟1,2,贺鹏飞2,李毅君2,3. BL-代数的严格滤子[J]. 山东大学学报(理学版), 2014, 49(03): 63 -67 .