Full Papers
the ranges of AcOH (1.59–8.26 mol%), O2 (2.8–8.8 mol%), C2H4 (7.8–
37.6 mol%) and argon. The gas space hourly velocities (GSHV) were
equal to 15.06, 15.92 and 22.80 Nm3/(h.kgcat). Initially, 500 mg of
catalysts were reduced with pure H2, from room temperature up to
3008C, at heating rate of 58C/min. Afterwards, the samples were
cooled with He to 1508C. The outlet gas stream was monitored by
gas chromatography (CP-3110 Varian, Santa Clara, USA) equipped
with two separation columns (Poraplot U, Carboxen 1006 plot) and
two detectors (FID, TCD) for three temperatures (150, 180, 2008C).
The individual conversions of the reactants (C2H4, O2 and AcOH)
and the selectivities in dry basis were calculated in accordance with
Equations (10) and (11), respectively.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
Keywords: vinyl acetate · PdꢀCu; ZrO2-Al+3 · ZrO2-Ti+4 · DRIFTS
[1] A. W. Budiman, J. S. Nam, J. H. Park, R. I. Mukti, T. S. Chang, J. W. Bae,
M. J. Choi, Catal. Surv. Asia 2016, 20, 173–193.
[2] F. W. Speetjens, M. K. Mahanthappa, Macromolecules 2015, 48, 5412–
5422.
[3] N. Ben Halima, RSC Adv. 2016, 6, 39823–39832.
[4] M. Chen, D. Kumar, C.-W. Yi, D. W. Goodman, Science. 2015, 310, 291–
300.
[5] M. S. Chen, K. Luo, T. Wei, Z. Yan, D. kumar, C. W. Yi, D. W. Goodman,
Catal. Today. 2006, 117, 37–45.
[6] D. Yuan, X. Gong, R. Wu, J. Phys. Chem. C. 2008, 112, 1539–1543.
[7] M. Garcꢁa-Mota, N. Lꢂpez, J. Am. Chem. Soc. 2008, 130, 14406–14407.
[8] F. Gao, D. W. Goodman, Chem. Soc. Rev. 2012, 41, 8009–8020.
[9] E. K. Hanrieder, A. Jentys, J. A. Lercher, J. Catal. 2016, 333, 71–77.
[10] E. K. Hanrieder, A. Jentys, J. A. Lercher, ACS Catal. 2015, 5, 5776–5786.
[11] M. B. Gawande, A. Goswami, F. X. Felpin, T. Asefa, X. X. Huang, R. Silva,
X. X. Zou, R. Zboril, S. Varma, Chem. Rev. 2016, 116, 3722–3811.
[12] D. J. Stacchiola, Acc. Chem. Res. 2015, 48, 2151–2158.
[13] K. V. R. Chary, G. V. Sagar, C. S. Srikanth, V. V. Rao, J. Phys. Chem. B. 2007,
111, 543–550.
Fj ꢀFj
0
*
Xj¼
Sj¼
100
ð10Þ
ð11Þ
Fj
0
FJ
FT
*
100
where Fj is the outlet molar flow of reactant j (C2H4, O2 and AcOH);
Fj0 is the inlet molar flow of reactant j (C2H4, O2 and AcOH); FT is the
total flow and Sj is the selectivity for product
[14] Y. Zhu, Y. Zhu, G. Ding, S. Zhu, H. Zheng, Y. Li, Appl. Catal. A 2013, 468,
296–304.
[15] H. Zhang, Z. Wang, S. Li, Y. Jiao, J. Wang, Q. Zhu, X. Li, Appl. Therm. Eng.
2017, 111, 811–818.
[16] E. Hernꢃndez-Ramirez, J. A. Wang, L. F. Chen, M. A. Valenzuela, A. K.
Dalai, Appl. Surf. Sci. 2017, 399, 77–85.
22 In situ DRIFT Spectroscopy
23
[17] J. Gu, Y.-W. Zhang, F. (Feng) Tao, Chem. Soc. Rev. 2012, 8050–8065.
[18] G. Zhao, F. Yang, Z. Chen, Q. Liu, Y. Ji, Y. Zhang, Z. Niu, J. Mao, X. Bao, P.
Hu, Y. Li, Nat. Commun. 2017, 8, 14039.
[19] J. H. Bang, K. S. Suslick, Adv. Mater. 2010, 22, 1039–1059.
[20] Y. Xu, L. Chen, X. Wang, W. Yao, Q. Zhang, Nanoscale 2015, 7, 10559–
10583.
[21] G. Roscher, Ullmann’s Ency. Ind. Chem., Vol. 38. Wiley-VCH Verlag GmbH
& Co. KGaA, 2000. pp 107–123.
[22] D. D. Kragten, R. A. van Santen, M. K. Crawford, W. D. Provine, J. J. Lerou,
Inorg. Chem. 1999, 38, 331–339.
24 The in situ DRIFTS-MS analyses were performed on a Thermo
25 Nicolet spectrometer (Nexus 470, USA), equipped with an
26 MCTꢀA detector, with resolution of 4 cmꢀ1 and in a high-
27 temperature chamber (SpectraTech) with ZnSe windows. The
28 outlet line of the chamber was coupled to a Pfeiffer mass
29 spectrometer; model QMS Prisma (Aßlar, Germany), equipped
30 with the CH-TRON detector. The catalyst was pre-treated in situ
31 under H2 flow (40 mL/min) from room temperature to 300 0C, at
[23] M. Sankar, N. Dimitratos, P. J. Miedziak, P. P. Wells, C. J. Kiely, G. J.
Hutchings, Chem. Soc. Rev. 2012, 8099–8139.
0
32 heating rate of 5 C/min for 1 h. Then, the sample was cooled
33 down to 1508C. AcOH was saturated for 1 h, to stabilize the
34 AcOH concentration. Afterwards, the O2 flow (20 mL/min, 5
35 vol% in He) and the C2H4 flow (10 mL/min) were adjusted.
36 Reagents were mixed in the mass flow controller passing
37 through the saturator. Spectra were taken using the reduced
38 sample as background and stored as averages of 150 scans. The
39 reaction was carried out for 1 h at each temperature (150, 180,
40 2008C) and the spectra were obtained after 10 minutes of
41 reaction. Then, the surface was cleaned with helium to remove
42 AcOH, C2H4 and O2, and analyzed. Finally, the temperature was
43 adjusted for the next condition.
[24] X. Li, X. Wang, M. Liu, H. Liu, Q. Chen, Y. Yin, M. Jin, Nano Res. 2018, 11,
780–790.
[25] H. Li, X. Zhao, H. Liu, S. Chen, X. Yang, C. Lv, H. Zhang, X. She, D. Yang,
Small 2018, 14, 1802824.
[26] M. D. Marcinkowski, A. D. Jewell, M. Stamatakis, M. B. Boucher, E. A.
Lewis, C. J. Murphy, G. Kyriakou, E. C. H. Sykes, Nat. Mater. 2013, 12,
523–528.
[27] G. X. Pei, X. Y. Liu, X. Yang, L. Zhang, A. Wang, L. Li, H. Wang, X. Wang, T.
Zhang, ACS Cat. 2017, 7, 1491–1500.
[28] Y. Liu, Y. He, D. Zhou, J. Feng, D. Li, Catal. Sci. Technol. 2016, 6, 3027–
3037.
[29] Axel, G, J. Phys. Condens. Matter 2009, 21, 084205.
[30] X. Cao, A. Mirjalili, J. Wheeler, W. Xie, B. W. L. Jang, Front. Chem. Sci. Eng.
2015, 9, 442–449.
[31] Z. Xu, L. Chen, Y. Shao, D. Yin, S. Zheng, Ind. Eng. Chem. Res. 2009, 48,
8356–8363.
44
45
[32] X. Cao, Y. Ji, Y. Luo, J. Phys. Chem. C. 2015, 119, 1016–1023.
[33] S. Shan, V. Petkov, B. Prasai, J. Wu, P. Joseph, Z. Skeete, E. Kim, D. Mott,
O. Malis, J. Luo, Nanoscale 2015, 7, 18936–18948.
[34] K. A. Goulas, S. Sreekumar, Y. Song, P. Kharidehal, G. Gunbas, P. J.
Dietrich, G. R. Johnson, Y. C. Wang, A. M. Grippo, L. C. Grabow, J. Am.
Chem. Soc. 2016, 138, 6805–6812.
46 Acknowledgments
47
48 The authors thank CNPq (Conselho Nacional de Desenvolvimento
49 Cientıfico e Tecnologico. Brazil) for financial support and scholar-
´
´
[35] F. Cai, L. Yang, S. Shan, D. Mott, B. Chen, J. Luo, C.-J. Zhong, Catalysts
2016, 6, 96.
´
ˆ
50 ships. The authors also thank Nucleo de Microscopia Eletronica
51 (COPPE/UFRJ) for TEM analyses and CBPF for the XPS analyses.
52
53
54 Conflict of Interest
55
56 The authors declare no conflict of interest.
57
[36] J. Gu, Y. W. Zhang, F. Tao, Chem. Soc. Rev. 2012, 41, 8050–8065.
[37] F. R. Lucci, J. Liu, M. D. Marcinkowski, M. Yang, L. F. Allard, M. Flytzani-
Stephanopoulos, E. C. H. Sykes, Nat. Commun. 2015, 6.
[38] A. R. Gonzꢃlez, Y. J. O. Asencios, E. M. Assaf, J. M. Assaf, Appl. Surf. Sci.
2013, 280, 876–877.
[39] F. M. Anzures, F. C. Rivas, J. H. Ventura, P. S. Hernꢃndez, G. Berlier, G.
Zacahua-Tlacuatl, Appl. Catal. A 2015, 489, 218–225.
[40] P. Estifaee, M. Haghighi, N. Mohammadi, F. Rahmani, Ultrason.
Sonochem. 2014, 21, 1155–1165.
ChemCatChem 2018, 10, 5256–5269
5268
ꢀ 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim