不同碳化铁物相的Fe@C催化剂对CO_(2)加氢的影响  

Effect of Fe@C Catalysts with Different Iron Carbide Phases on CO_(2) Hydrogenation

作　　者：蔡紫微 吕帅[1] 张煜华[1] 王立[1] 李金林[1] CAI Ziwei;LV Shuai;ZHANG Yuhua;WANG Li;LI Jinlin(Key Laboratory of Catalysis and Energy Materials Chemistry of Ministry of Education & Hubei Key Laboratory of Catalysis and Materials Science,South-Central Minzu University,Wuhan 430074,China)

机构地区：[1]中南民族大学,催化转化与能源材料化学教育部重点实验室,催化材料科学湖北省重点实验室,湖北武汉430074

出　　处：《化学与生物工程》2022年第5期13-16,31,共5页Chemistry & Bioengineering

基　　金：国家自然科学基金项目(22072184,21972170)。

摘　　要：Fe基催化剂因其优秀的逆水煤气变换活性常用于CO_(2)加氢制备烃类和含氧化合物。以Fe@C催化剂为前体,通过调控催化剂预处理条件,获得了不同物相的碳化铁,考察了碳化铁物相对CO_(2)加氢性能的影响。结果表明:高温焙烧得到的Fe@C催化剂主要物相是θ-Fe_(3)C;氢气还原后的Fe@C-R催化剂的主要物相是ε-Fe_(2)C;先经氢气还原处理,再利用合成气原位碳化的Fe@C-R-C催化剂的主要物相是χ-Fe_(5)C_(2);θ-Fe_(3)C物相具有较高的CO_(2)转化率(35.2%)和较低的甲烷选择性(28.0%),甲醇产率72.8μmol·g^(-1)·h^(-1),且在反应过程中非常稳定;ε-Fe_(2)C物相具有较高的甲醇产率(160.8μmol·g^(-1)·h^(-1)),但是甲烷选择性(41.7%)过高;χ-Fe_(5)C_(2)物相活性相对较低,甲烷选择性(40.0%)较高,甲醇产率(48.4μmol·g^(-1)·h^(-1))较低。Fe-based catalysts are often used as catalysts for CO_(2) hydrogenation to produce hydrocarbons and oxygenates because of their excellent reverse water gas shift activity.Herein,using Fe@C catalyst as a precursor,we obtained different iron carbide phases by adjusting the pretreatment conditions of the catalyst,and investigated the effect of iron carbide phases on CO_(2) hydrogenation.The results show that the main phase of Fe@C catalyst prepared by high temperature calcination isθ-Fe_(3)C,the main phase of Fe@C-R catalyst prepared by hydrogen reduction isε-Fe_(2)C;meanwhile,the main phase of Fe@C-R-C catalyst which is firstly prepared by hydrogen reduction and then in-situ carbonated by syngas isχ-Fe_(5)C_(2).Theθ-Fe_(3)C phase exhibits a high CO_(2) conversion rate of 35.2%,low methane selectivity of 28.0%,and the methanol yield of 72.8μmol·g^(-1)·h^(-1),which is very stable during the reaction process.Theε-Fe_(2)C phase has high methanol yield of 160.8μmol·g^(-1)·h^(-1),but much high methane selectivity of 41.7%.Theχ-Fe_(5)C_(2) phase has relatively low activity,high methane selectivity of 40.0%,and lower methanol yield of 48.4μmol·g^(-1)·h^(-1).

关 键 词：CO_(2)加氢 碳化铁物相 构效关系 

分 类 号：O621.254[理学—有机化学]