The electrocarboxylation reaction is an attractive means to convert CO2 into valuable chemicals under ambient conditions,while it still suffers from low efficiency due to the high stability of CO2.In this work,w...The electrocarboxylation reaction is an attractive means to convert CO2 into valuable chemicals under ambient conditions,while it still suffers from low efficiency due to the high stability of CO2.In this work,we report a double activation strategy for simultaneously activating CO2 and acetophenone by silver-doped CeO2(Ag-CeO2) nanowires,featuring as an effective electrocatalyst for electrocarboxylation of acetophenone with CO2.Compared to the Ag foil,Ag nanoparticles and CeO2 nanowires,the Ag-CeO2nanowire catalyst allowed to reduce the onset potential difference between CO2 and acetophenone activation,thus enabling efficient electrocarboxylation to form 2-phenyllactic acid.The Faradaic efficiency for producing 2-phenyllactic acid reached 91%at−1.8 V versus Ag/AgI.This double activation strategy of activating both CO2and organic substrate molecules can benefit the catalyst design to improve activities and selectivities in upgrading CO2fixation for higher-value electrocarboxylation.展开更多
为更有效脱除空气中甲醛污染物,分别将CeO_2、MnO_x-CeO_2和Ag/MnO_x-CeO_2催化剂与介质阻挡放电等离子体结合,在大气压及35℃下脱除空气中甲醛,选取脱除效果最好的Ag/MnO_xCeO_2为催化剂,研究放电电压和HCHO初始体积分数以及空速对HCH...为更有效脱除空气中甲醛污染物,分别将CeO_2、MnO_x-CeO_2和Ag/MnO_x-CeO_2催化剂与介质阻挡放电等离子体结合,在大气压及35℃下脱除空气中甲醛,选取脱除效果最好的Ag/MnO_xCeO_2为催化剂,研究放电电压和HCHO初始体积分数以及空速对HCHO脱除率的影响。结果表明,当空气中甲醛的体积分数为2.0×10-4、水的体积分数为1.0%、空速为16 364 h-1、放电电压为18 k V时,Ag/MnO_x-CeO_2与等离子体结合的甲醛脱除率达99.0%,高出单纯等离子体和单纯Ag/MnO_x-CeO_2催化氧化(不放电)脱除率之和23.9%。实验证明,在脱除空气中HCHO的过程中,Ag/MnO_x-CeO_2与等离子体结合产生了很强的协同作用,且等离子体中的活性物种是协同作用的关键。展开更多
摘要The electrocarboxylation reaction is an attractive means to convert CO2 into valuable chemicals under ambient conditions,while it still suffers from low efficiency due to the high stability of CO2.In this work,we report a double activation strategy for simultaneously activating CO2 and acetophenone by silver-doped CeO2(Ag-CeO2) nanowires,featuring as an effective electrocatalyst for electrocarboxylation of acetophenone with CO2.Compared to the Ag foil,Ag nanoparticles and CeO2 nanowires,the Ag-CeO2nanowire catalyst allowed to reduce the onset potential difference between CO2 and acetophenone activation,thus enabling efficient electrocarboxylation to form 2-phenyllactic acid.The Faradaic efficiency for producing 2-phenyllactic acid reached 91%at−1.8 V versus Ag/AgI.This double activation strategy of activating both CO2and organic substrate molecules can benefit the catalyst design to improve activities and selectivities in upgrading CO2fixation for higher-value electrocarboxylation.
摘要为更有效脱除空气中甲醛污染物,分别将CeO_2、MnO_x-CeO_2和Ag/MnO_x-CeO_2催化剂与介质阻挡放电等离子体结合,在大气压及35℃下脱除空气中甲醛,选取脱除效果最好的Ag/MnO_xCeO_2为催化剂,研究放电电压和HCHO初始体积分数以及空速对HCHO脱除率的影响。结果表明,当空气中甲醛的体积分数为2.0×10-4、水的体积分数为1.0%、空速为16 364 h-1、放电电压为18 k V时,Ag/MnO_x-CeO_2与等离子体结合的甲醛脱除率达99.0%,高出单纯等离子体和单纯Ag/MnO_x-CeO_2催化氧化(不放电)脱除率之和23.9%。实验证明,在脱除空气中HCHO的过程中,Ag/MnO_x-CeO_2与等离子体结合产生了很强的协同作用,且等离子体中的活性物种是协同作用的关键。
摘要以锐钛矿TiO_2为载体,考察了CeO_2改性对Ag-CeO_2-V_2O_5/TiO_2催化3-甲基吡啶氧化脱甲基性能的影响,并优化了催化剂组成与制备条件.结果表明:Ce掺杂改性不仅能够与V物种作用形成Ce VO_4,而且促进V_2O_5分散,改善活性组分的氧化还原性能,从而提高3-甲基吡啶脱甲基转化率与选择性,改善Ag-V_2O_5/TiO_2催化性能.适宜的催化剂组成为V_2O_5负载量15%,Ce/V的摩尔比0.33,Ag质量分数1.0%.过高的焙烧温度将导致TiO_2载体向金红石型转变,Ag-CeO_2-V_2O_5/TiO_2适宜制备条件为450℃焙烧4 h.