LaCuZnX (X=Al, Zr, Al+Zr) perovskite-like catalysts treated by NaBH4 and their catalytic performance for CO2 hydrogenation to methanol
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摘要: 通过并流沉淀法制备出La：Cu：Zn：X（X=Zr、Al、Zr+Al）（类）钙钛矿型催化剂，并使用NaBH4作为还原剂进行液相还原。将催化剂装填在固定床反应器中并用于CO2加氢制甲醇的性能评价，并通过一系列表征方法对催化剂的物化性能进行了测试。结果表明，所制备的催化剂主要具有La2CuO4（类）钙钛矿结构，并且在该结构中掺入元素后将导致（类）钙钛矿结构的空间扭曲。经NaBH4还原后，结构中存在金属铜物种和部分未还原的高价态铜物种，在反应过程中会发生高价态铜物种的还原。相比于LaCuZn催化剂，Al元素的引入提高了CO2的转化率，Zr元素的引入，降低了催化剂的催化活性，Al和Zr元素同时引入提高了CO2转化率和甲醇的收率。LCZA催化剂CO2转化率最高，LCZ催化剂甲醇选择性最高，LCZZA催化剂甲醇时空收率最高。CO2转化率和催化剂的Cu的比表面积、Cu的分散度、（Cuα++Cu0）/Cutotal呈正相关；催化剂Cuα+的结合能越远离Cu+，相应催化剂的甲醇选择性越高。Abstract: La:Cu:Zn:X (X=Zr, Al, Al+Zr) perovskite-like catalysts were prepared by coprecipitation method followed by liquid phase reduction by NaBH4. The physicochemical properties of the catalysts were tested by a series of characterization methods, and the catalysts were tested for methanol synthesis from CO2 hydrogenation in a fixed-bed reactor. The results showed that the as-prepared catalysts were mainly composed of La2CuO4 perovskite-like crystal structure and doping of elements led to the spatial distortion of the perovskite-like structure. After reduction by NaBH4, metal copper species and some high-valence copper species were found, which could be further reduced during the reaction. The CO2 conversion was positively correlated with the Cu surface area, the dispersion of Cu, and the (Cuα++Cu0)/Cutotal of the catalyst. The higher methanol selectivity was obtained when Cuα+ binding energy was farther away from Cu+ binding energy. LCZA had the highest CO2 conversion, LCZ catalyst possessed the highest methanol selectivity, and LCZZA catalyst presented the optimal methanol space time yield.
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Key words:
- CO2 hydrogenation /
- methanol /
- perovskite-like /
- liquid reduction method
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图 3 催化剂的Cu 2p XPS能谱和Cu LMM俄歇能谱谱图
Figure 3 Cu 2p XPS and Cu LMM Auger electron spectroscopies of the catalysts
图 4 催化剂的La 3d(a)、Zr 3d(b)和Al 2p(c) XPS能谱谱图
Figure 4 La 3d, Zr 3d and Al 2p XPS of the catalysts
图 7 CO2转化率与ACu、DCu、(Cuα++Cu0)/Cutotal关系图以及甲醇选择性与Cuα+结合能关系图
Figure 7 Relationship between CO2 conversion and CO2 conversion and ACu (a), DCu (b), CO2 conversion and (Cuα++Cu0)/Cutotal (c), methanol selectivity and binding energy of Cuα+ (d)
图 8 甲醇选择性与碱性位关系图
Figure 8 Relationship between methanol selectivity and basic sites of the catalysts
表 1 催化剂的结构参数
Table 1 Structural parameters of the catalysts
Catalyst ABETa/(m2·g-1) Pore volumea v/(cm3·g-1) Pore sizea d/nm DCub/% ACub/(m2·g-1) LCZ 12 0.036 12.0 7.52 1.68 LCZZ 9 0.032 13.2 3.18 1.52 LCZA 6 0.031 19.3 17.98 2.96 LCZZA 10 0.046 18.3 11.03 2.54 a: the data were obtained by N2 desorption experiment; b: the data were calculated from N2O adsorption experiments 
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表 2 催化剂的碱位数目及各碱位所占的比例
Table 2 Basicity and the distribution of basic sites over the catalysts
Catalyst Relative contenta of each basic site and percentage of total basicity α peak β peak γ peak total basicity LCZ 1.0(1.39%) 20.8(28.89%) 50.2(69.72%) 72.0 LCZZ 2.6(3.07%) 24.8(29.28%) 57.3(67.65%) 84.7 LCZA 1.8(4.99%) 13.8(38.23%) 20.5(56.79%) 36.1 LCZZA 2.9(7.25%) 17.1(42.75%) 20.0(50.00%) 40.0
a: calculate the relative content of other samples with the LCZ sample as 1.0 reference
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表 3 催化剂活性反应评价
Table 3 Evaluation data of the catalysts
Catalyst xCO2/% sCH3OH/% wCH3OH/(g·mL-1·h-1) LCZ 10.8 59.0 0.09 LCZZ 6.6 49.9 0.05 LCZA 13.2 42.4 0.08 LCZZA 12.2 53.0 0.11 reaction conditions: p=5.0 MPa, t=250 ℃, n(H2)/n(CO2)=3:1, GHSV=4000 h-1
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[1] CHOUDHURY J. New strategies for CO2-to-methanol conversion[J]. ChemCatChem, 2012, 4(5):609-611. doi: 10.1002/cctc.201100495 [2] OLAH G A. Beyond oil and gas:The methanol economy[J]. Angew Chem Int Ed, 2005, 44(18):2636-2639. doi: 10.1002/anie.200462121 [3] DU X L, JIANG Z, SU D S, WANG J Q. Research progress on the indirect hydrogenation of carbon dioxide to methanol[J]. ChemSusChem, 2016, 9(4):322-332. doi: 10.1002/cssc.201501013 [4] SLOCZYNSKI J, GRABOWSKI R, KOZLOWSKA A, OLSZEWSKI P, STOCH J, SKRZYPEK J, LACHOWSKA M. Catalytic activity of the M/(3ZnO center dot ZrO2) system (M=Cu, Ag, Au) in the hydrogenation of CO2 to methanol[J]. Appl Catal A:Gen, 2004, 278(1):11-23. doi: 10.1016/j.apcata.2004.09.014 [5] KATTEL S, YAN B, YANG Y, CHEN J G, LIU P. Optimizing binding energies of key intermediates for CO2 hydrogenation to methanol over oxide-supported copper[J]. J Am Chem Soc, 2016, 138(38):12440-12450. doi: 10.1021/jacs.6b05791 [6] GUO X, MAO D, LU G, WANG S, WU G. The influence of La doping on the catalytic behavior of Cu/ZrO2 for methanol synthesis from CO2 hydrogenation[J]. J Mol Catal A:Chem, 2011, 345(1/2):60-68. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=e78981eb9f339ada505c245ba0c19971 [7] ZHANG Y L, SUN Q, DENG J F, WU D, CHEN S Y. A high activity Cu/ZnO/Al2O3 catalyst for methanol synthesis:Preparation and catalytic properties[J]. Appl Catal A:Gen, 1997, 158(1/2):105-120. doi: 10.1016/S0926-860X(96)00362-6 [8] DENG J F, SUN Q, ZHANG Y L, CHEN S Y, WU D. A novel process for preparation of a Cu/ZnO/Al2O3 ultrafine catalyst for methanol synthesis from CO2+H2:Comparison of various preparation methods[J]. Appl Catal A:Gen, 1996, 139(1/2):75-85. https://www.researchgate.net/publication/263380583_Preparation_Structure_and_Performance_of_CuO-ZnO-Al2O3_HZSM-5_Core-Shell_Bifunctional_Catalysts_for_One-Step_Synthesis_of_Dimethyl_Ether_from_CO2H2 [9] SUN Q, ZHANG Y L, CHEN H Y, DENG J F, WU D, CHEN S Y. Novel process for the preparation of Cu/ZnO and Cu/ZnO/Al2O3 ultrafine catalyst:Structure, surface properties, and activity for methanol synthesis from CO2+H2[J]. J Catal, 1997, 167(1):92-105. doi: 10.1006/jcat.1997.1554 [10] WANG D, TAO F, ZHAO H, SONG H, CHOU L. Preparation of Cu/ZnO/Al2O3 catalyst for CO2 hydrogenation to methanol by CO2 assisted aging[J]. Chin J Catal, 2011, 32(9):1452-1456. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=cuihuaxb201109003 [11] CHEN C S, WU J H, LAI T W. Carbon dioxide hydrogenation on Cu nanoparticles[J]. J Phys Chem C, 2010, 114(35):15021-15028. doi: 10.1021/jp104890c [12] FISHER I A, BELL A T. In situ infrared study of methanol synthesis from H2/CO over Cu/SiO2 and Cu/ZrO2/SiO2[J]. J Catal, 1998, 178(1):153-173. doi: 10.1006/jcat.1998.2134 [13] WANG Z Q, XU Z N, ZHANG M J, CHEN Q S, CHEN Y, GUO G C. Insight into composition evolution in the synthesis of high-performance Cu/SiO2 catalysts for CO2 hydrogenation[J]. Rsc Adv, 2016, 6(30):25185-25190. doi: 10.1039/C6RA02929A [14] GRABOWSKA E. Selected perovskite oxides:Characterization, preparation and photocatalytic properties-A review[J]. Appl Catal B:Environ, 2016, 186:97-126. doi: 10.1016/j.apcatb.2015.12.035 [15] ZHAN H, LI F, GAO P, ZHAO N, XIAO F, WEI W, SUN Y. Influence of element doping on La-Mn-Cu-O based perovskite precursors for methanol synthesis from CO2/H2[J]. Rsc Adv, 2014, 4(90):48888-48896. doi: 10.1039/C4RA07692C [16] ZHAN H, LI F, XIN C, ZHAO N, XIAO F, WEI W, SUN Y. Performance of the La-Mn-Zn-Cu-O based perovskite precursors for methanol synthesis from CO2 hydrogenation[J]. Catal Lett, 2015, 145(5):1177-1185. doi: 10.1007/s10562-015-1513-8 [17] BELIN S, BRACEY C L, BRIOIS V, ELLIS P R, HUTCHINGS G J, HYDE T I, SANKAR G. 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 [18] CHEN L C, LIN S D. The ethanol steam reforming over Cu-Ni/SiO2 catalysts:Effect of Cu/Ni ratio[J]. Appl Catal B:Environ, 2011, 106(3/4):639-649. https://www.sciencedirect.com/science/article/abs/pii/S0926337311003043 [19] LIAW B J, CHEN Y Z. Catalysis of ultrafine CuB catalyst for hydrogenation of olefinic and carbonyl groups[J]. Appl Catal A:Gen, 2000, 196(2):199-207. doi: 10.1016/S0926-860X(99)00464-0 [20] YUAN Z, WANG L, WANG J, XIA S, CHEN P, HOU Z, ZHENG X. Hydrogenolysis of glycerol over homogenously dispersed copper on solid base catalysts[J]. Appl Catal B:Environ, 2011, 101(3/4):431-440. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=94e7f00688faea6c205fb8e769aebb9e [21] YANG R, YU X, ZHANG Y, LI W, TSUBAKI N. A new method of low-temperature methanol synthesis on Cu/ZnO/Al2O3 catalysts from CO/CO2/H2[J]. Fuel, 2008, 87(4/5):443-450. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=6cc8ee0616e4d8d4eaa6dd5c21587fba [22] POKROVSKI K A, RHODES M D, BELL A T. Effects of cerium incorporation into zirconia on the activity of Cu/ZrO2 for methanol synthesis via CO hydrogenation[J]. J Catal, 2005, 235(2):368-377. doi: 10.1016/j.jcat.2005.09.002 [23] MESHKINI F, TAGHIZADEH M, BAHMANI M. Investigating the effect of metal oxide additives on the properties of Cu/ZnO/Al2O3 catalysts in methanol synthesis from syngas using factorial experimental design[J]. Fuel, 2010, 89(1):170-175. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=c93bfb0181a6d18c15ee98f92af9ea20 [24] MALUF S S, NASCENTE P A P, AFONSO C R M, ASSAF E M. Study of La2-xCaxCuO4 perovskites for the low temperature water gas shift reaction[J]. Appl Catal A:Gen, 2012, 413:85-93. doi: 10.1016/j.apcata.2011.10.047 [25] KARELOVIC A, BARGIBANT A, FERNANDEZ C, RUIZ P. Effect of the structural and morphological properties of Cu/ZnO catalysts prepared by citrate method on their activity toward methanol synthesis from CO2 and H2 under mild reaction conditions[J]. Catal Today, 2012, 197(1):109-118. doi: 10.1016/j.cattod.2012.07.029 [26] GAO P, LI F, XIAO F, ZHAO N, SUN N, WEI W, ZHONG L, SUN Y. Preparation and activity of Cu/Zn/Al/Zr catalysts via hydrotalcite-containing precursors for methanol synthesis from CO2 hydrogenation[J]. Catal Sci Technol, 2012, 2(7):1447-1454. doi: 10.1039/c2cy00481j [27] ZHAN H, LI F, GAO P, ZHAO N, XIAO F, WEI W, ZHONG L, SUN Y. Methanol synthesis from CO2 hydrogenation over La-M-Cu-Zn-O (M=Y, Ce, Mg, Zr) catalysts derived from perovskite-type precursors[J]. J Power Sources, 2014, 251:113-121. doi: 10.1016/j.jpowsour.2013.11.037 [28] ARENA F, ITALIANO G, BARBERA K, BORDIGA S, BONURA G, SPADARO L, FRUSTERI F. Solid-state interactions, adsorption sites and functionality of Cu-ZnO/ZrO2 catalysts in the CO2 hydrogenation to CH3OH[J]. Appl Catal A:Gen, 2008, 350(1):16-23. doi: 10.1016/j.apcata.2008.07.028 [29] ARENA F, ITALIANO G, BARBERA K, BONURA G, SPADARO L, FRUSTERI F. Basic evidences for methanol-synthesis catalyst design[J]. Catal Today, 2009, 143(1/2):80-85. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=b686cb9ab074c2239dca91be205589d9 [30] ZHU Y F, TAN R Q, YI T, GAO S, YAN C H, CAO L L. Preparation of nanosized La2CuO4 perovskite oxide using an amorphous heteronuclear complex as a precursor at low-temperature[J]. J Alloys Compd, 2000, 311(1):16-21. doi: 10.1016/S0925-8388(00)00851-3 [31] KUMAR B V, VELCHURI R, PRASAD G, SREEDHAR B, RAVIKUMAR K, VITHAL, M. Preparation, characterization, photoactivity and XPS studies of Ln(2)ZrTiO(7) (Ln=Sm and Nd)[J]. Ceram Int, 2010, 36(4):1347-1355. doi: 10.1016/j.ceramint.2010.01.019 [32] The U S. Secretary of Commerce on behalf of the United States of America. NIST X-ray Photoelectron Spectroscopy Database[DB/OL].https: //srdata.nist.gov/xps/Default.aspx, 2000-06-06/2019-12-01. [33] GAO P, LI F, ZHAN H, ZHAO N, XIAO F, WEI W, ZHONG L, WANG H, SUN Y. Influence of Zr on the performance of Cu/Zn/Al/Zr catalysts via hydrotalcite-like precursors for CO2 hydrogenation to methanol[J]. J Catal, 2013, 298:51-60. doi: 10.1016/j.jcat.2012.10.030 [34] WU G, WANG X, WEI W, SUN Y. Fluorine-modified Mg-Al mixed oxides:A solid base with variable basic sites and tunable basicity[J]. Appl Catal A:Gen, 2010, 377(1/2):107-113. doi: 10.1016/j.apcata.2010.01.023 [35] LIU Y, SUN K, MA H, XU X, WANG X. Cr, Zr-incorporated hydrotalcites and their application in the synthesis of isophorone[J]. Catal Commun, 2010, 11(10):880-883. doi: 10.1016/j.catcom.2010.03.014 [36] ARENA F, MEZZATESTA G, ZAFARANA G, TRUNFIO G, FRUSTERI F, SPADARO L. Effects of oxide carriers on surface functionality and process performance of the Cu-ZnO system in the synthesis of methanol via CO2 hydrogenation[J]. J Catal, 2013, 300:141-151. doi: 10.1016/j.jcat.2012.12.019 [37] WAUGH K C. The absorption and locking-in of hydrogen in copper[J]. Solid State Ionics, 2004, 168(3/4):327-342. doi: 10.1016/j.ssi.2003.05.001 [38] DONG X, LI F, ZHAO N, XIAO F, WANG J, TAN Y. CO2 hydrogenation to methanol over Cu/ZnO/ZrO2 catalysts prepared by precipitation-reduction method[J]. Appl Catal B:Environ, 2016, 191:8-17. doi: 10.1016/j.apcatb.2016.03.014 [39] GAO P, LI F, ZHAO N, XIAO F, WEI W, ZHONG L, SUN Y. Influence of modifier (Mn, La, Ce, Zr and Y) on the performance of Cu/Zn/Al catalysts via hydrotalcite-like precursors for CO2 hydrogenation to methanol[J]. Appl Catal A:Gen, 2013, 468:442-452. doi: 10.1016/j.apcata.2013.09.026 -
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