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载体颗粒尺寸对Pd/γ-Al_(2)O_(3)催化氧化苯甲醇性能影响
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作者 王哲 李晓良 史荣会 《精细化工中间体》 CAS 2024年第5期35-41,共7页
为了探究载体粒径尺寸对Pd/γ-Al_(2)O_(3)催化性能的影响,分别以微米级γ-Al_(2)O_(3)-V和纳米级γ-Al_(2)O_(3)-N为载体,通过浸渍法负载活性组分Pd,然后将制备的Pd/γ-Al_(2)O_(3)用于苯甲醇无溶剂催化氧化研究。实验结果表明:在苯甲... 为了探究载体粒径尺寸对Pd/γ-Al_(2)O_(3)催化性能的影响,分别以微米级γ-Al_(2)O_(3)-V和纳米级γ-Al_(2)O_(3)-N为载体,通过浸渍法负载活性组分Pd,然后将制备的Pd/γ-Al_(2)O_(3)用于苯甲醇无溶剂催化氧化研究。实验结果表明:在苯甲醇催化氧化反应过程中,γ-Al_(2)O_(3)的颗粒尺寸对Pd基催化剂的催化活性具有显著影响,相较于Pd/γ-Al_(2)O_(3)-V(Ea=127.4 kJ/mol),载体颗粒尺寸更小的Pd/γ-Al_(2)O_(3)-N(Ea=82.1 kJ/mol)具有更低的反应活化能,从而具有更高的催化活性。通过X射线衍射(XRD)、N_(2)物理吸附(N_(2)-BET)、电感耦合等离子体原子发射光谱(ICP-AES)、透射电子显微镜(TEM)和X射线光电子能谱(XPS)分析,发现由载体差异引起的较小的Pd纳米颗粒尺寸、较大的孔容和孔径及表面较为丰富的Pd^(0)物种是纳米级Pd/γ-Al_(2)O_(3)-N取得优异催化性能的关键。 展开更多
关键词 pd/γ-Al_(2)O_(3) 载体颗粒尺寸 苯甲醇 催化氧化 无溶剂
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Non-Gaussian noise-enhanced stochastic rate oscillations in CO oxidation on nanometer-sized Pd particles
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作者 GONG YuBing LIN Xiu HAO YingHang 《Science China Chemistry》 SCIE EI CAS 2010年第11期2343-2348,共6页
The effect of non-Gaussian colored noise(NGN),mainly its departure q from the Gaussian noise,on the optimal ISRO of CO oxidation on nanometer-sized Pd particles was studied.It was found that the ISRO in the absence of... The effect of non-Gaussian colored noise(NGN),mainly its departure q from the Gaussian noise,on the optimal ISRO of CO oxidation on nanometer-sized Pd particles was studied.It was found that the ISRO in the absence of external noise can still be enhanced when the NGN is applied.Specifically,the ISRO varies with changing q and becomes more regular at an appropriate q value,and when q is optimal,the ISRO becomes the most regular.Because the departure q from the Gaussian noise determines the probability distribution function and hence may denote the types of noise,this result shows that different types of external noise can enhance the ISRO of CO oxidation,and non-Gaussian noise may enhance the ISRO more greatly than the Gaussian noise.Therefore,non-Gaussian noise could play more effective roles in the catalytic process of CO oxidation on nanometer-sized Pd particles. 展开更多
关键词 non-Gaussian colored noise catalytic co oxidation on nanometer pd particles intrinsic stochastic rate oscillation coherence resonance
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钙钛矿型 LaCoO_(3-δ)和 La_(1-x)Sr_xCo O_(3 -δ)纳米粒子的 XPS表征 被引量:16
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作者 郝茂荣 刘源 +2 位作者 崔秀兰 何菲 秦永宁 《燃料化学学报》 EI CAS CSCD 北大核心 1999年第4期309-313,共5页
采用XPS等手段对LaCoO3-δ和La1-xSrxCoO3-δ纳米粒子进行了表征。结果显示,随LaCoO3-δ纳米粒子粒径的减小,一方面表面钴浓度增加,另一方面,表面CoO键的离子性增强和表面氧空位浓度增加。此二者... 采用XPS等手段对LaCoO3-δ和La1-xSrxCoO3-δ纳米粒子进行了表征。结果显示,随LaCoO3-δ纳米粒子粒径的减小,一方面表面钴浓度增加,另一方面,表面CoO键的离子性增强和表面氧空位浓度增加。此二者共同导致LaCoO3-δ对一氧化碳氧化的催化活性随其粒径减小而明显增大。LaCoO3-δ纳米粒子中镧被锶部分取代后,其表面结构发生了变化。 展开更多
关键词 钙钛矿型 稀土复合氧化物 纳米粒子 XPS 催化剂
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Internal noise stochastic resonance in CO oxidation on nm-sized palladium particles 被引量:2
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作者 GONG Yubing1,2, HOU Zhonghuai1 & XIN Houwen1 1. Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, China 2. Department of Physics, Yantai Teachers University, Yantai 264025, China 《Science China Chemistry》 SCIE EI CAS 2005年第5期395-401,共7页
Based on a stochastic mesoscopic model, the influence of internal noise on the oscillatory kinetics of the catalytic oxidation of CO on nm-sized palladium particles is studied, using the chemical Langevin equations, P... Based on a stochastic mesoscopic model, the influence of internal noise on the oscillatory kinetics of the catalytic oxidation of CO on nm-sized palladium particles is studied, using the chemical Langevin equations, Poisson approximation algorithm, and exact stochastic simulation algorithm. The reaction rate oscillations are of stochastic nature due to considerable internal noise in such mesoscopic systems. It is found that the performance of the stochastic oscillations undergoes a maximum with the variation of internal noise level for a given CO partial pressure, which demonstrates the occurrence of internal noise stochastic resonance. This phe-nomenon implies that optimal internal noise would favor the reaction rate oscillation of CO oxi-dation on nm particles. Such a phenomenon is robust to the change of external parameters, such as CO pressures. 展开更多
关键词 nanometer-sized PALLADIUM particles surface catalytic co oxidation internal noise stochastic resonance chemical LANGEVIN equation.
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CO在纳米CeO_2负载的Pd-Cu催化剂上的低温催化氧化 被引量:3
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作者 张敬超 张玉军 +2 位作者 谭砂砾 郑华 德王磊 《化学通报》 CAS CSCD 北大核心 2005年第1期66-69,共4页
用溶胶_凝胶法制得了平均晶粒度为 1 5nm的CeO2 粉体 ,并用浸渍法制备了Pd_Cu 纳米CeO2 催化剂 ;通过XRD、SEM和HRTEM等表征手段研究了纳米CeO2 粉体和Pd_Cu 纳米CeO2 催化剂的性能 ;考察了催化剂对CO的低温催化氧化活性。结果表明 :纳... 用溶胶_凝胶法制得了平均晶粒度为 1 5nm的CeO2 粉体 ,并用浸渍法制备了Pd_Cu 纳米CeO2 催化剂 ;通过XRD、SEM和HRTEM等表征手段研究了纳米CeO2 粉体和Pd_Cu 纳米CeO2 催化剂的性能 ;考察了催化剂对CO的低温催化氧化活性。结果表明 :纳米CeO2 粉体负载的Pd_Cu催化剂对CO的低温催化氧化活性明显优于一般CeO2 颗粒负载的Pd_Cu催化剂 ,其CO完全氧化的最低温度比Pd_Cu 热分解法CeO2 催化剂低约 70℃ ,比Pd_Cu 工业CeO2 催化剂低约 1 3 0℃。因此 ,纳米CeO2 粉体作载体可极大地提高Pd_Cu催化剂的CO氧化性能。 展开更多
关键词 催化剂 纳米CEO2 粉体 催化氧化 并用 co氧化 溶胶一凝胶法 最低温度 平均 表征
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