CoMoK／γ－Al_2O_3水煤气变换催化剂的硫化及反硫化

以Ｈ＿２Ｓ和ＣＳ＿２作硫化剂，用ＴＰＳ和ＴＰＤＳ方法研究了水媒气变换催化剂ＣｏＭｏＫ／γ－Ａｌ＿２Ｏ＿３的硫化及反硫化过程。用Ｈ＿２Ｓ／Ｈ＿２硫化时，只发现Ｈ＿２Ｓ的消耗和Ｈ＿２Ｏ的生成，用ＣＳ＿２／Ｈ＿２硫化时，首先生成ＣＯ＿２，然后是ＣＨ＿４，Ｈ＿２Ｏ和Ｈ＿２Ｓ，ＴＰＧ实验表明催化剂表面上有积炭，造成催化剂的活性降低。但积炭在水煤气变换反应进行中逐渐除去。ＴＰＤＳ实验表明Ｎ＿２不起反硫化作用，Ｈ＿２和ＣＯ也没有明显反硫化作用，Ｈ＿２Ｏ对ＣｏＭｏＫ／γ－Ａｌ＿２Ｏ＿３催化剂有根强的反硫化作用。Ｏ＿２能使催化剂部分永久性失活。ＸＰＳ测试表明反硫化的催化剂中低价的Ｍｏ￣（４＋）转变成高价的Ｍｏ￣（５＋）和Ｍｏ￣（６＋），导致其活性下降。     

COS对FT合成催化性能的影响

在５２４Ｋ、２．３１ＭＰａ和１８４５ｈ＾－１条件下，考察了合成气（Ｈ２／ＣＯ＝２．１）中ＣＯＳ浓度分别为５１．４、１２８．８、１６２．７和２４５．６ｐｐｍ对Ｆｅ－Ｃｕ－Ｋ工业催化剂ＦＴ合成催化性能的影响。实验表明，催化剂预先中毒比在线中毒速度快。大颗粒催化剂的抗硫能力比小颗粒催化剂强。催化剂ＦＴ合成失活速率与ＣＯＳ浓度有关，即高浓度条件下，催化剂的失活速率快。当温度为５２４Ｋ时，催化剂的失活速率最     

Co－Mo／TiO_2和C0－M0／γ－Al_2O_3加氢脱硫催化剂的研究

本文考察了ＣｏＭｏ／ＴｉＯ３和ＣｏＭｏ／γ－Ａｌ２Ｏ３催化剂的加氢脱硫性能及表面结构变化和预处理条件对其活性的影响．担体ＴｉＯ２（Ａ）和ＴｉＯ２（Ｂ）分别采用ＴｉＣｌ４中和法和ＴｉＯＳＯ４水解法制备．结果表明，催化剂的活性顺序为ＣｏＭｏ／ＴｉＯ２（Ａ）＞ＣｏＭｏ／ＴｉＯ２（Ｂ）＞ＣｏＭｏ／γ－Ａｌ２Ｏ３催化剂的预处理条件对催化剂的加氢脱硫（ＨＤＳ）和加氢（ＨＹＤ）活性有很大影响，ＴｉＯ２担体上Ｍｏ物种主要以八面体配位构型存在，Ｍｏ６＋更易于还原成低价态．     

以ZrO2-Al2O3为载体的Co-Mo-K耐硫水煤气变换催化剂

采用沉淀法和浸渍法分别制备了ＺｒＯ２－Ａｌ２Ｏ３复合载体和Ｃｏ－Ｍｏ－Ｋ耐硫变换催化剂。研究了ＺｒＯ２对Ｃｏ－Ｍｏ－Ｋ面硫变换催化剂活性及热稳定性的影响。利用ＸＲＤ、ＢＥＴ、ＴＧ、ＸＰＳ等手段对催化剂及其载体的结构、吸硫吸水性能和氧化还原性能进行了表征。结果表明以ＺｒＯ２－Ａｌ２Ｏ３代替传统的γ－Ａｌ２Ｏ３作为Ｃｏ－Ｍｏ－Ｋ耐硫变换催化剂的载体,可提高催化剂的活性,尤其是低温活性,并可改善催化剂的     

载体对负载钴催化剂CH4/CO2重整反应的影响

采用固定床微反应器,利用ＸＲＤ及ＴＰＲ技术研究了载体对负载于γ－Ａｌ２Ｏ３、Ｓｉ２、ＨＺＳＭ－５分子筛上的Ｃｏ催化剂合成气反应性整制合成气反应性能的影响。结果表明,金属与载体之间的相互是影响催化剂活性化和稳定性的重要因素,ＨＺＳＭ－５是一种优功体,但硅铝比较低易积炭,Ｃｏ／ＳｉＯ２及低功量的Ｃｏ／Ａｌ２Ｏ３催化知必氏易失活,其失活原因前为Ｃｏ＾０晶粒的烧结,后为Ｃｏ＾０向ＣｏＡｌ２Ｏ４转变。探     

高硫合成气制甲硫醇K2MoS4／SiO2催化剂

高硫合成气制甲硫醇Ｋ_２ＭｏＳ_４／ＳｉＯ_２催化剂杨意泉，车长针，袁友珠，方钦和，林国栋，张鸿斌（厦门大学化学系，厦门大学物理化学研究所，厦门３６１００５）关键词负载型Ｋ_２ＭｏＳ_４／ＳｉＯ_２催化剂，甲硫醇，Ｈ_２Ｓ１．前言甲硫醇是合成蛋氨酸的重要原...     

Mo－Fe／SiO_2催化剂中钼流失动力学和流失机理的研究

作为甲醇氧化制甲醛、甲醇氨氧化制ＨＣＮ反应的催化剂，其活性组分钼的流失是导致催化剂失活的主要原因。本文结合程序升温脱附（ＴＰＤ）及Ｘ－光衍射（ＸＲＤ）等测试手段，对Ｍｏ－Ｆｅ／ＳｉＯ_２催化剂及工业实际用多元复合钼催化剂中钼的流失动力学和机理进行了研究。在ＨＣＮ合成过程中，水能引起活性组分钼的流失，而水又是反应产物。对工业用多元复合钼催化剂的流失情况进行了动力学考察，实验发现，催化剂中的钼是较难流失的，ＸＲＤ测试结果表明，Ｍｏ－Ｆｅ／ＳｉＯ_２催化剂中的钼是以Ｆｅ_２（ＭｏＯ_４）_３晶体形式存在的，而反应后催化剂中Ｍｏ为ＭｏＯ_３晶体状态。与其它催化剂比较，ＭｏＯ_３／ＳｉＯ_２催化剂中的钼难流失，而较Ｂｉ－Ｍｏ／ＳｉＯ_２催化剂中的钼易流失。其中工业用催化剂是最为稳定的。根据实验结果，结合我们以前的工作，证明Ｍｏ－Ｆｅ／ＳｉＯ_２催化剂中，由于钼组分和铁组分的相互作用，使得Ｍｏ－Ｆｅ／ＳｉＯ_２中的Ｍｏ的流失难于单组分的ＭｏＯ_３／ＳｉＯ_２催化剂，此外钼流失过程中ＭｏＯ_２（ＯＨ）_２与催化剂中铁组分反应生成钼酸盐的倾向也是Ｍｏ难于流失的原因之一。而Ｍｏ－Ｆｅ／ＳｉＯ_２和Ｍｏ－Ｂｉ／ＳｉＯ_２催化剂中钼流失速度的差异     

Co-Mo/TiO2和Co-Mo/γ-Al2O3加氢脱硫催化剂的研究

本文考察了ＣｏＭｏ／ＴｉＯ２和ＣｏＭｏ／γ－Ａｌ２Ｏ３催化剂的加氢脱硫性能及表面结构变化和处理条件对其活性的影响，担体ＴｉＯ２（Ａ）和ＴｉＯ２（Ｂ）分别采用ＴｉＯＳＯ４水解法制备，结果表明，催化剂的活性顺序为ＣｏＭｏ／ＴｉＯ２（Ａ）＞ＣｏＭｏ／ＴｉＯ２（Ｂ）＞ＣｏＭｏ／γ－Ａｌ２Ｏ３，催化剂的预处理条件对催化剂的加氢脱硫和加氢活性有很大影响，ＴｉＯ２担体上Ｍｏ物种主要以八面体配位构型存在，Ｍｏ＾－     

以ZrO2—Al2O3为载体Co—Mo—K耐硫变换催化剂的TPR研究

利用程序升温还原（ＴＰＲ）技术,研究了ＺｒＯ２对Ｃｏ／Ａｌ２Ｏ３、Ｍｏ／Ａｌ２Ｏ３、Ｍｏ－Ｋ／Ａｌ２Ｏ３以及Ｃｏ－Ｍｏ－Ｋ耐硫催化剂氧化还原性能的影响。结果表明,ＺｒＯ２的引入,使活性组分在载体表面分散的更好,促进了Ｍｏ－Ｋ活性相的形成,使ｏ和Ｍｏ的还原变得容易,并起到抑制催化剂在反应中被重新氧化的作用。     

SO_4~(2-)/ZrO_2催化剂上正丁烷异构化反应

考察了活化温度、反应温度、空速、Ｈ２／Ｃ４比和载Ｐｔ对ＳＯ２－４／ＺｒＯ２催化剂的正丁烷异构化反应活性和稳定性的影响．较高的Ｈ２／Ｃ４比可提高ＳＯ２－４／ＺｒＯ２催化剂的稳定性和稳态活性．催化剂负载Ｐｔ后，可降低反应原料中的Ｈ２／Ｃ４比．积炭是造成反应初始阶段催化剂迅速失活的主要原因，经烧炭再生以后这部分失活可以完全恢复     

KINETICS OF SULFUR POISONING IN A FIXED BED FOR F-T SYNTHESIS OVER COMMERCIAL Fe-Cu-KCATALYST

IntroductionSulfurpoisoningofanironcatal}'stisoneofthemostseriousdcactivationproblemsincomn'crcialproductionofsubstitutingnaturalgasforcoalreportedb}'Bartholomc\\ofal.II1andAndersonofal.12I.Thecommercialco-precipitatedFo-Cu-Kcatal\'stpreparedb}'Instituteo…     

Deactivation Mechanism for COS Hydrolysis over TGH Catalyst --- FT-IR Study of the

The adsorptions of COS, H2S and O2 were investigated over the TGH catalyst in this paper.It was found that the numbers of basic centers and basic intensities were reduced over the deactivated TGH catalyst. The FT-IR results of COS+H2S+O2 co-adsorption on the TGH catalyst show that the main causes of catalyst deactivation is the formation of element sulfur and trace sulfate.     

硫化NiW/Al2O3催化剂上H2同时催化还原SO2和NOⅠ.NO的分解与还原

 考察了NO在硫化NiW/Al2O3催化剂上分解和还原的规律. 结果表明,在350 ℃以上,NO完全分解,但同时催化剂的晶格硫因氧化而以SO2的形式大量流失,最终导致催化剂完全失活. 在NO分解反应体系中,按化学计量比引入的H2与晶格硫竞争消耗NO分解所生成的Oad,使晶格硫的氧化在一定程度上得到抑制; 氧化的部分晶格硫能通过一系列氧化还原过程重新进入催化剂晶格,导致晶格硫的流失速度和程度得到缓和,催化剂可在较长的时间内保持较高的NO转化活性. 但是,催化剂的活性最终仍会因为大部分晶格硫逐渐流失而大幅度下降.     

Deactivation Mechanism for COS Hydrolysis over TGH Catalyst——FT-IR Study of the Adsorption Behavior of COS,O_2 and H_2S

The adsorptions of COS, H2S and O2 were investigated over the TGH catalyst in this paper. It was found that the numbers of basic centers and basic intensities were reduced over the deactivated TGH catalyst. The PT-IR results of COS+H2S+O2 co-adsorption on the TGH catalyst show that the main causes of catalyst deactivation is the formation of element sulfur and trace sulfate.     

Formation of sulfur surface species on a commercial NO<Subscript>x</Subscript>-storage reduction catalyst

The influence of SO₂ exposure under lean (oxidizing) and rich (reducing) reaction conditions on the storage and oxidation/reduction function of a commercial NO_x storage-reduction catalyst was investigated by temperature-programmed uptake experiments and high temperature XRD. Both the storage capacity and the oxidation/reduction function of the catalyst were deactivated by SO₂ exposure under lean and rich reaction conditions. The deactivation of the storage component, i.e. the loss of the NO_x storage capacity, resulted mainly from the formation of Ba-sulfates accumulating in the bulk phase, which have a high thermal stability (>800°C) and, therefore, cannot be removed under the typical operation conditions of a NSR catalyst. For the oxidation function only a temporarily deactivation during lean reaction conditions was observed. Besides the formation of SO^2- ₄ species on the storage component at the beginning of the SO₂ exposure under rich conditions, an adsorption of SO₂ on the noble metal component was observed resulting in the formation of sulfur deposits. The oxidation of these sulfur species with a subsequent spillover of SO^2- ₄ species to the storage component during lean conditions could accelerate the deactivation of the storage capacity.     

Deactivation studies of nano-structured iron catalyst in Fischer-Tropsch synthesis

A nano-structured iron catalyst for syngas conversion to hydrocarbons in Fischer-Tropsch synthesis (FTS) was prepared by micro-emulsion method. Compositions of bulk iron phase and phase transformations of carbonaceous species during catalyst deactivation in FTS reaction were characterized by temperature-programmed surface reaction with hydrogen (TPSR-H2), and XRD techniques. Many carbonaceous species on surface and bulk of the nano-structured iron catalysts were completely identified by combined TPSR-H2 and XRD spectra and which were compared with those recorded on conventional co-precipitated iron catalyst. The results reveal that the catalyst deactivation results from the formation of inactive carbide phases and surface carbonaceous species like graphite, and it will be increased when the particle size of iron oxides was reduced in FTS iron catalyst.     

Purification Influence of Synthesis Gas Derived from Methanol Cracking on the Performance of Cobalt Catalyst in Fischer-Tropsch Synthesis

1. Introduction Fischer-Tropsch synthesis (FTS) has gained in- dustrial attention for converting synthesis gas to high- boiling points waxes that can be further converted to sulfur-free motor fuels by hydrogenation or hydroc- racking as alternative resour…     

燃煤电厂SCR催化剂的失活及再生实验研究

对某燃煤电站脱硝系统已运行24000 h的SCR催化剂进行活性测试,利用XRD、BET、XRF、FT-IR和XPS等表征手段分析发现,催化剂出现微、中孔堵塞及活性物质氧化等问题,导致催化剂失活。采用水洗和酸洗方法清除催化剂孔道中的堵塞物,发现水洗能还原部分V物质而酸洗能恢复催化剂表面的活性位并均匀负载具有提高活性位酸性作用的硫物种。对水洗后的催化剂进行SO_2硫化处理,发现相比酸洗Br■nsted和Lewis酸性位强度提高的同时Lewis酸性位密度也提高。再生处理后,酸洗在250℃以上活性恢复到新鲜催化剂水平,450℃硫化催化剂活性在380℃达到新鲜催化剂活性的104.6%。     

XAFS STUDIES OF IRON CATALYSTS FOR F-T SYNTHESIS

IntroductionX-rnyabsorptionfinestructure(XAFS)spectroscopeprovidesauniqucopportunitytodetermincthcstructureofnanophasesystemswithshort-rangeorder,suchascatalystslllAnalysisofthcextendedpartofX-rayabsorptionfincstructure(EXAFS)providesthcinformationaboutthcidcntity,intefatomicdistanccs,andcoordinationnumbcrofatomsintheneghboringatomicshellssurroundingthccentralabsorbingatomFortransitionmetalcompondswithincompletelyfilleddshellthesamepre-edgepcaksintheX-rayabsorptionncar-edgestructure(XANE…