Reaseching on Supported Noble Metals over Mn⁃Zr Composite Oxides for the Catalytic Combustion of Vinyl Chloride

doi:10.3969/j.issn.1006-396X.2021.05.001

Abstract

Abstract:

The Mn?Zr composite oxides were prepared by co?precipitation,loading with noble metals(Ru,Pd,Pt) on the surfaces by a following impregnation method.The effects of noble metals on catalytic combustion of vinyl chloride (VC) were further investigated.The structure and chemical state,the oxidation?reduction ability and acidity,the distribution of acid over the noble metal loading catalysts were studied.Noble metals exist in the form of oxidation state on catalyst surface to promote the reduction of Mn?Zr composite oxides and improve the redox ability of the catalysts. In addition,noble metals not only increased total acid amount but also changed the distribution of Br?nsted and Lewis acid centers on catalyst surface.Therefore, the noble metal made the completely VC conversion temperature shift to lower temperature.However,the activities of noble metals for catalytic combustion of VC varied with the kind of noble metal.Among them,Ru had the more positively activity enhancement than that of Pd and Pt.The catalytic temperatures were 206 and 243 °C, when the VC conversion over Ru/MZ(Ru/Mn_0.7Zr_0.3O_x) reached to 50% (t₅₀) and 90% (t₉₀),respectively,which were 69 and 71 °C lower than that using Mn?Zr composite oxide.Meanwhile,the loading of noble metals also changed the composition of chlorinated by?products and reduced their concentration.The total concentration of chlorinated by?products over Ru/MZ catalyst was only 5.7 μL/L with 90% VC conversion rate,which was 70% lower than MZ composite oxide at the same conversion rate.

Key words: Vinyl chloride, Catalytic combustion, Noble metal, Mn?Zr oxides, Chlorinated by?products

摘要：

以共沉淀法制备了Mn?Zr复合氧化物，通过浸渍法引入贵金属(Ru、Pd、Pt)，考察了贵金属对于氯乙烯催化燃烧反应性能的影响；并对催化剂的结构和化学状态，氧化还原性能和酸性能，表面酸类型的分布特征进行表征。研究发现，贵金属主要以氧化态的形式存在于催化剂表面，贵金属的引入促进了复合氧化物的还原，从而提高了催化剂的氧化还原性能，同时也提高了催化剂表面酸的总量、改变了表面Br?nsted酸和Lewis酸中心的分布。贵金属引入后，促进了反应性能的提高，使得氯乙烯全转化温度向低温偏移；不同贵金属对于反应促进的效果不同，其中Ru的引入，对于反应的促进效果高于Pd和Pt的引入。Ru/MZ (Ru/Mn_0.7Zr_0.3O_x)催化剂上氯乙烯转化50%和90%的温度（t₅₀、t₉₀）分别为206、243 ℃，比纯复合氧化物催化剂的相应温度向低温偏移69、71 ℃。贵金属引入后也改变了有机含氯副产物的分布并降低了其浓度，Ru/MZ催化剂在t₉₀时的含氯副产物总体积分数为5.7 μL/L，比Mn_0.7Zr_0.3O_x在相同转化率下的有机氯代副产物体积分数低70%。

关键词: 氯乙烯, 催化燃烧, 贵金属, Mn?Zr氧化物, 含氯副产物

CLC Number:

TQ139.2

Tian Fang, Yiyin Gao, Siyu Wang, Li Wang, Yun Guo, Yanglong Guo. Reaseching on Supported Noble Metals over Mn⁃Zr Composite Oxides for the Catalytic Combustion of Vinyl Chloride[J]. Journal of Petrochemical Universities, 2021, 34(5): 1-8.

方田, 高奕吟, 王思雨, 王丽, 郭耘, 郭杨龙. Mn⁃Zr复合氧化物负载贵金属催化剂的氯乙烯催化燃烧性能[J]. 石油化工高等学校学报, 2021, 34(5): 1-8.

Figures/Tables 10

Fig.1 The activity curves of MnyZr1?yOx(y=0,0.2,0.4,0.5,0.7,1.0) catalysts for vinyl chloride

Fig. 2 The activity curves of supported noble metals catalysts for VC catalytic combustion

Fig. 3 The concentration of chloric by?products over Mn0.7Zr0.3Ox，Pt/MZ，Pd/MZ and Ru/MZ

Fig. 4 The Cl2 selectivity of supported noble metals catalysts

Table 1 The physical structure parameters and the data of H2 consumption, acid amount and XPS of supported precious metal catalysts

催化剂	比表面积^a （m² $⋅$ g^-1）	耗氢量^b/（mmol $⋅$ g^-1）	酸量^c/（mmol $⋅$ g^-1）		L酸酸量/B酸酸量^d	表面原子浓度比^c
催化剂	比表面积^a （m² $⋅$ g^-1）	耗氢量^b/（mmol $⋅$ g^-1）	中强酸	总酸量	L酸酸量/B酸酸量^d	Mⁿ⁺/M_total^e	O_β/O_α^e	Mn⁴⁺/ Mn_total^e
Mn_0.7Zr_0.3O_x	131.6	2.38	0.35	0.39	37.0	-	1.04	0.27
Ru/MZ	145.3	3.36	0.40	0.57	12.9	0.47	1.36	0.39
Pd/MZ	121.8	2.80	0.34	0.50	21.7	1.00	1.21	0.33
Pt/MZ	111.2	3.18	0.39	0.49	25.0	0.73	1.13	0.30

Table 1 The physical structure parameters and the data of H2 consumption, acid amount and XPS of supported precious metal catalysts

催化剂	比表面积^a （m² $⋅$ g^-1）	耗氢量^b/（mmol $⋅$ g^-1）	酸量^c/（mmol $⋅$ g^-1）		L酸酸量/B酸酸量^d	表面原子浓度比^c
催化剂	比表面积^a （m² $⋅$ g^-1）	耗氢量^b/（mmol $⋅$ g^-1）	中强酸	总酸量	L酸酸量/B酸酸量^d	Mⁿ⁺/M_total^e	O_β/O_α^e	Mn⁴⁺/ Mn_total^e
Mn_0.7Zr_0.3O_x	131.6	2.38	0.35	0.39	37.0	-	1.04	0.27
Ru/MZ	145.3	3.36	0.40	0.57	12.9	0.47	1.36	0.39
Pd/MZ	121.8	2.80	0.34	0.50	21.7	1.00	1.21	0.33
Pt/MZ	111.2	3.18	0.39	0.49	25.0	0.73	1.13	0.30

Fig. 5 XRD patterns of supported noble metals catalysts

Fig. 6 XPS spectra of supported noble metals catalysts

Fig. 7 H2?TPR profiles of supported noble metals catalysts

Fig. 8 NH3?TPD profiles of supported noble metals catalysts

Fig.9 Py?FT?IR spectra of supported noble metals catalysts

References 29

1	Huang B B，Lei C，Wei C H，et al.Chlorinated volatile organic compounds （Cl⁃VOCs） in environment ⁃ sources，potential human health impacts， and current remediation technologies［J］.Environment International，2014，71：118⁃138.
2	Dai C H，Zhou Y Y，Peng H，et al.Current progress in remediation of chlorinated volatile organic compounds：A review［J］. Journal of Industrial and Engineering Chemistry，2018，62：106⁃119.
3	汤清虎，刘婷婷，吴成明，等.Mn⁃Zr⁃O催化剂的制备及其催化苯甲醇氧化反应的活性［J］.石油化工，2012，41（11）：1253⁃1257.
	Tang Q H，Liu T T，Wu C M，et al.Preparation of Mn⁃Zr⁃O catalyst and its catalytic application in benzyl alcohol oxidation［J］.Petrochenmical Technology，2012，41（11）：1253⁃1257.
4	Zhang C H，Wang C，Hua W C，et al.Relationship between catalytic deactivation and physicochemical properties of LaMnO₃ perovskite catalyst during catalytic oxidation of vinyl chloride［J］.Applied Catalysis B：Environmental，2016，186：173⁃183.
5	Zhao B H，Ran R，Wu X D，et al.Comparative study of Mn/TiO₂ and Mn/ZrO₂ catalysts for NO oxidation［J］.Catalysis Communications，2014，56：36⁃40.
6	Jia J B，Ran R，Guo R Q，et al.ZrO₂⁃supported α⁃MnO₂： Improving low⁃temperature activity and stability for catalytic oxidation of methane［J］.Progress in Natural Science：Materials International，2018，28（3）：296⁃300.
7	Jong V D，Cieplik M K，Reints W A，et al.A mechanistic study on the catalytic combustion of benzene and chlorobenzene［J］.Journal of Catalysis，2002，211（2）：355⁃365.
8	Dai Y，Wang X Y，Dai Q G，et al. Effect of Ce and La on the structure and activity of MnOx catalyst in catalytic combustion of chlorobenzene［J］. Applied Catalysis B： Environmental，2012，111⁃112： 141⁃149.
9	Dai Q G，Wu J Y，Deng W，et al. Comparative studies of P/CeO₂ and Ru/CeO₂ catalysts for catalytic combustion of dichloromethane： From effects of H₂O to distribution of chlorinated by⁃products［J］. Applied Catalysis B： Environmental，2019，249： 9⁃18.
10	Wang C，Zhang C H，Hua W C，et al. Low⁃temperature catalytic oxidation of vinyl chloride over Ru modified Co₃O₄ catalysts［J］.RSC Advances，2016，6（101）： 99577⁃99585.
11	Wang L，Wang C，Xie H K，et al. Catalytic combustion of vinyl chloride over Sr doped LaMnO₃［J］. Catalysis Today，2019，327： 190⁃195.
12	Freyschlag C G，Madix R J. Precious metal magic： Catalytic wizardry［J］. Materials Today，2011，14（4）： 134⁃142.
13	Zhao J，Xi W，Tu C，et al. Catalytic oxidation of chlorinated VOCs over Ru/TixSn_1⁃x catalysts［J］. Applied Catalysis B： Environmental，2020，263：118237⁃118251.
14	Dai Q G，Bai S X，Wang X Y，et al. Catalytic combustion of chlorobenzene over Ru⁃doped ceria catalysts： Mechanism study［J］. Applied Catalysis B： Environmental，2013，129： 580⁃588.
15	Dai Q G，Bai S X，Wang Z Y，et al. Catalytic combustion of chlorobenzene over Ru⁃doped ceria catalysts［J］. Applied Catalysis B： Environmental，2012，126： 64⁃75.
16	Hua W C，Zhang C H，Guo Y L，et al. An efficient SnyMn_1⁃yOx composite oxide catalyst for catalytic combustion of vinyl chloride emissions［J］. Applied Catalysis B： Environmental，2019，255：117748⁃117757.
17	Gu Y F，Shao S J，Sun W，et al. The oxidation of chlorinated organic compounds over W⁃modified Pt/CeO₂ catalysts［J］. Journal of Catalysis，2019，380： 375⁃386.
18	Teschner D，Farra R，Yao L，et al. An integrated approach to Deacon chemistry on RuO₂⁃based catalysts［J］. Journal of Catalysis，2012，285（1）： 273⁃284.
19	Zhang A C，Zhang Z H，Lu H，et al. Effect of promotion with Ru addition on the activity and SO₂ resistance of MnOx–TiO₂ adsorbent for Hg⁰ removal［J］. Industrial & Engineering Chemistry Research，2015，54（11）： 2930⁃2939.
20	Liao W M，Fang X X，Cen B H，et al. Deep oxidation of propane over WO₃⁃ promoted Pt/BN catalysts： The critical role of Pt ⁃ WO₃ interface［J］. Applied Catalysis B： Environmental，2020，272：118858⁃118868.
21	Murata K，Kosuge D，Ohyama J，et al. Exploiting metal–support interactions to tune the redox properties of supported Pd catalysts for methane combustion［J］. ACS Catalysis，2019，10（2）： 1381⁃1387.
22	Singh P，Hegde M S. Ce_1⁃xRuxO_2⁃δ（x=0.05，0.10）： A new high oxygen storage material and Pt，Pd⁃free three⁃way catalyst［J］. Chemistry of Materials，2009，21（14）： 3337⁃3345.
23	Machocki A，Ioannides T，Stasinska B，et al. Manganese–lanthanum oxides modified with silver for the catalytic combustion of methane［J］. Journal of Catalysis，2004，227（2）： 282⁃296.
24	Wang G，Wang Y，Qin L B，et al. Efficient and stable degradation of chlorobenzene over a porous iron–manganese oxide supported ruthenium catalyst［J］. Catalysis Science & Technology，2020，10（21）： 7203⁃7216.
25	丁天朋，赵伟，孟明，等.CuMn₂TiO₆催化剂的制备及其甲烷催化燃烧性能［J］.石油化工，2015，44（12）：1518⁃1523.
	Ding T P，Zhao W，Meng M，et al. Preparation of CuMn₂TiO₆ and its activities in catalytic combustion of methane［J］. Petrochenmical Technology，2015，44（12）： 1518⁃1523.
26	Wang G，Wang Y，Qin L B，et al. Efficient and stable degradation of chlorobenzene over a porous iron–manganese oxide supported ruthenium catalyst［J］. Catalysis Science & Technology，2020，10（21）： 7203⁃7216.
27	Kim H D，Park H J，Kim T W，et al. Hydrogen production through the aqueous phase reforming of ethylene glycol over supported Pt⁃based bimetallic catalysts［J］. International Journal of Hydrogen Energy，2012，37（10）： 8310⁃8317.
28	袁灿，刘绍英，姚洁，等. Co₉CrO_z/HZSM⁃5催化剂催化氧化低浓度氯乙烯［J］. 石油化工，2019，48（2）： 95⁃102.
	Yuan C，Liu S Y，Yao J，et al. Catalytic oxidation of low concentration vinyl chloride over Co₉CrO_z/HZSM⁃5 catalyts［J］. Petrochenmical Technology，2019，48（2）： 95⁃102.
29	Wang X C，Yu J C，Liu P，et al. Probing of photocatalytic surface sites on SO42-/TiO₂ solid acids by in situ FT⁃IR spectroscopy and pyridine adsorption［J］. Journal of Photochemistry & Photobiology A Chemistry，2006，179（3）： 339⁃347.

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