Effect of ZnO on Cu/ZnO/Al_2O_3 catalysts for methanol synthesis

[中文文摘]用高速碰撞共沉淀法制备m(CuO) /m(ZnO) /m(Al2 O3 )比分别为 60 /3 0 /1 0和 3 0 /60 /1 0的 1 #和 2 #催化剂 ,结果表明高ZnO的 2 #催化剂活性较好 ,分散度较大。XPS测试表明 2 #催化剂表面ZnO吸附的中间体 (CHx 或CHxO)较多且表面的Cu+1浓度较高 ,从而促进CO加氢合成甲醇的活性。[英文文摘]Cu/ZnO/Al_2O_3 catalysts with ratios of 60/30/10 and 30/60/10 have been prepared by high speed collision coprecipitation method. The performance of the catalyst with the higher ZnO content shows the higher activity in methanol synthesis. The characterization results indicated that the catalyst with the higher ZnO content has higher dispersion. On the surface of the higher ZnO content catalyst, there was more Cu+1 and more intermediate (CH_x and CH_xO) adsorpted. It is beneficial for the CO hydrogenating to produce methanol

Deuterium Inverse Isotopic Effect in Ammonia Synthesis over Ru-Based and Fe-Based Catalysts

联系人: 林敬东.Tel:(0592)2183045;Fax:(0592)2183043; E-mail: [email protected] 廖代伟. Tel:(0592)2183045;Fax:(0592)2183043; E-mail: [email protected][中文文摘]氘反同位素效应是合理阐明过渡金属催化剂上氨合成催化反应机理的重要实验依据之一.在N2/H2(或D2)体积比1/3,0.2MPa,633～733K和GHSV=24000或12000h-1的条件下,检测到了Ru基(纯Ru,Ru/γ-Al2O3,K-Ru/γ-Al2O3,Ru/MgO,K-Ru/MgO和Ba-Ru/MgO)和Fe基(纯Fe和A110-3)催化剂上强的氘反同位素效应(rD/rH≈2),其数值随催化剂和反应温度的变化而变化.这可能是动力学同位素效应与热力学同位素效应二者相互强竞争的结果.[英文文摘]The deuterium inverse isotopic effect (DIIE) is important for the clarification of the ammonia synthesis mechanism over transition metal catalysts. We investigated the DIIE over Ru-based and Fe-based catalysts including pure Fe,multi-promoted fused Fe,pure Ru,Ru/γ-Al2O3,K-Ru/γ-Al2O3,Ru/MgO,K-Ru/MgO,and Ba-Ru/MgO under the reaction conditions of N2/H2 (or D2) volume ratio = 1/3,0.2 MPa,633–733 K,and GHSV = 24 000 and 12 000 h?1. A strong DIIE (rD/rH of about 2) was observed over the above catalysts. The trend of the DIIE with catalysts and temperature indicated a strong competition between the dynamic and thermodynamic factors.国家自然科学基金(20673089);国家重点基础研究发展计划(973计划,2009CB939804

Some Effects of Co on the Electrochromic Properties of NiO xH y Film

本文利用阴极化电沉积法在抛光镍板及ＩＴＯ玻璃表面制备了含Ｃｏ量为１６．２％的ＮｉＯｘＨｙ薄膜，薄膜厚度分别为４２ｎｍ、２１ｎｍ，采用透射光谱以及线性电位扫描、交流阻抗和阳极稳态极化曲线等测试技术，考察了Ｃｏ对ＮｉＯｘＨｙ薄膜电致变色性能的影响，光谱测试范围为３００～２５００ｎｍ．结果发现：Ｃｏ能降低薄膜着色态在可见光区及部分近红外区的透过率，通过电压调节不仅可以调光而且可望能够控温；同时Ｃｏ还能降低ＮｉＯｘＨｙ薄膜电致变色电位，升高薄膜氧化着色过程中的氧析出过电位，对薄膜的电致变色性能有改进作用，但降低了着色过程中质子的扩散系数．Some effects of Co addition upon the electrochromic characteristics of a nic_kel hydroxide film were studied. The films were electrodeposited on both polished Ni plate and conductive ITO glass. The electrochemical behaviors were investigated using the film on Ni plate by linear potential sweep, a.c. impedance, and anodic polarization curves for OER(oxygen evolution reaction). It was found that Co can lower the working voltage and raise the oxygen overpotential, but has little effect on the reaction kinetics. It was also found that the Co can improve the optical properties of the electrochromic film.作者联系地址：南开大学新能源材料化学研究所Author's Address: Inst. of New Energy Material Chem. Nankai Univ., Tianjin 30007

表面氧浓度对负载型金属催化剂活化甲烷反应性能的影响

利用脉冲 质谱在线分析技术考察了无气相氧条件下负载型金属催化剂上脉冲CH4的反应结果表明 ,对于Rh/SiO2 催化剂 ,不管是氧化态还是还原态 ,除第 1次脉冲生成较多的CO2 外 ,从第 2次脉冲开始 ,只有CO生成 ;对于Ru/SiO2 催化剂 ,无论是氧化态还是还原态 ,每次脉冲均有一定量的CO2 生成 .这可能是由于Rh和Ru两种金属对氧的亲合力不同所致 .甲烷在负载型催化剂表面的活化以及产物的选择性主要受催化剂表面活性氧物种覆盖度的影响

甲烷在Rh/SiO_2催化剂表面解离的红外光谱研究

FT-IR spectroscopy is employed to investigate the methane dissociation and methane partial oxidation over the Rh/SiO 2 catalyst. When CH 4 is adsorbed onto the catalyst surface, it dissociates into adsorbed CH x (x=1～3) and atomic hydrogen on Rh surface. Atomic hydrogen can diffuse from Rh surface to SiO 2 surface where a proton exchange reaction of H with the surface Si-OH occurs, or it reacts with the lattice oxygen of SiO 2 to form new Si-OH

福建鲍产业发展形势分析

鲍,素有\"软黄金\"的美誉。自上世纪90年代开始,福建引入皱纹盘鲍与日本盘鲍的杂交鲍并逐渐扩大养殖规模。笔者归纳了福建省鲍的养殖分布及生产情况,结合鲍的消费结构及产业支撑现状发现鲍产业发展过程中的育苗场规划,养殖管理,种质退化,安全用药等方面存在问题,对此提出推进科学养殖,增强环保意识;加强管理制度建设,实现质量监管;加强种质管理,选育新品种;加强技术体系建设;提升产业融合度等建议

表面氧浓度对负载型金属催化剂活化甲烷反应性能的影响

利用脉冲 质谱在线分析技术考察了无气相氧条件下负载型金属催化剂上脉冲CH4的反应结果表明 ,对于Rh/SiO2 催化剂 ,不管是氧化态还是还原态 ,除第 1次脉冲生成较多的CO2 外 ,从第 2次脉冲开始 ,只有CO生成 ;对于Ru/SiO2 催化剂 ,无论是氧化态还是还原态 ,每次脉冲均有一定量的CO2 生成 .这可能是由于Rh和Ru两种金属对氧的亲合力不同所致 .甲烷在负载型催化剂表面的活化以及产物的选择性主要受催化剂表面活性氧物种覆盖度的影响

Mechanism and isotope effect of ammonia synthesis over Fe and Ru catalysts

Chemistry for Catalyst Synthesis Division of Catalysis Science and Technology (probationary) The 237th ACS National Meeting, Salt Lake City, UT, March 22-26, 200

Ambient nitrate switches the ammonium consumption pathway in the euphotic ocean

高树基教授研究团队的研究论文，以现场原位速率观测与环境因子调查，证明了环境硝酸盐浓度是调控海洋真光层不同氨氮消耗途径的关键因子。硝酸盐通过影响浮游植物对于氨氮吸收的能力，决定了真光层内氨氮的氧化路径强弱，刻画了海洋真光层氮循环的微结构。高树基团队利用同位素示踪培养技术，围绕南海和西北太平洋真光层内硝化作用和浮游植物氨氮吸收速率的垂直分布特点及其动力学特征进行研究。首次提出硝酸盐浓度通过影响不同浮游植物类群对于氨氮的吸收能力，从而调控真光层的氨氮消耗途径。研究团队的万显会博士为成果的第一作者，近海海洋环境科学国家重点实验室的戴民汉教授，史大林教授、张瑶教授、盛华夏博士后、祝依凡，以及澳大利亚联邦科学与工业研究组的Tom Trull教授和美国Bigelow海洋实验室的Mike Lomas教授为成果的共同完成人。【Abstract】Phytoplankton assimilation and microbial oxidation of ammonium are two critical conversion pathways in the marine nitrogen cycle. The underlying regulatory mechanisms of these two competing processes remain unclear. Here we show that ambient nitrate acts as a key variable to bifurcate ammonium flow through assimilation or oxidation, and the depth of the nitracline represents a robust spatial boundary between ammonium assimilators and oxidizers in the stratified ocean. Profiles of ammonium utilization show that phytoplankton assemblages in nitrate-depleted regimes have higher ammonium affinity than nitrifiers. In nitrate replete conditions, by contrast, phytoplankton reduce their ammonium reliance and thus enhance the success of nitrifiers. This finding helps to explain existing discrepancies in the understanding of light inhibition of surface nitrification in the global ocean, and provides further insights into the spatial linkages between oceanic nitrification and new production.This work is supported by the National Natural Science Foundation of China through grants 91328207, Science Fund for Creative Research Groups of the National Natural Science Foundation of China through grants 41721005 and National Basic Research Program of China (973 Program) through grants 2014CB953702, 2015CB954003. T.W.T. was supported by an MEL Visiting Scholar award. 成果获得了国家重点基础研究发展计划（2014CB953702, 2015CB954003），国家自然科学基金委“创新研究群体项目”（41721005）以及重点基金（91328207）的资助

Direct conversion of methane to formaldehyde and CO on B2O3 catalysts

甲烷作为天然气的主要成分，是非常重要的碳基资源。不过，甲烷分子的化学惰性使得其转化通常需要在高温条件下进行，反应选择性难于控制。如何实现甲烷的高选择性定向转化一直是化学研究中的重要挑战，甚至被誉为化学领域的“圣杯”。化学化工学院王帅教授与华盛顿州立大学王勇教授合作在甲烷选择氧化反应非金属硼基催化剂的研究中取得重要进展，本研究中发现负载型氧化硼催化剂在甲烷直接氧化反应中表现出优异的抗深度氧化能力。本研究工作是在王帅教授和王勇教授的共同指导下完成。2015级博士生田金树（已毕业）、硕士生谈江乔（已毕业）以及醇醚酯清洁生产国家工程实验室张朝霞工程师为共同第一作者，林敬东副教授和万绍隆副教授等参与了部分研究和讨论。【Abstract】Direct oxidation of methane to value-added C1 chemicals (e.g. HCHO and CO) provides a promising way to utilize natural gas sources under relatively mild conditions. Such conversions remain, however, a key selectivity challenge, resulting from the facile formation of undesired fully-oxidized CO2. Here we show that B2O3-based catalysts are selective in the direct conversion of methane to HCHO and CO (~94% selectivity with a HCHO/CO ratio of ~1 at 6% conversion) and highly stable (over 100 hour time-on-stream operation) conducted in a fixed-bed reactor (550 °C, 100 kPa, space velocity 4650 mL gcat−1 h−1 ). Combined catalyst characterization, kinetic studies, and isotopic labeling experiments unveil that molecular O2 bonded to tri-coordinated BO3 centers on B2O3 surfaces acts as a judicious oxidant for methane activation with mitigated CO2 formation, even at high O2/CH4 ratios of the feed. These findings shed light on the great potential of designing innovative catalytic processes for the direct conversion of alkanes to fuels/chemicals.This work was supported by the National Natural Science Foundation of China (No. 21922201, 21872113, 91945301, 21673189, and 91545114) and the Fundamental Research Funds for the Central Universities (No. 20720190036 and 20720160032).研究工作得到了国家自然科学基金（21922201、21872113、91945301、21673189、91545114）和中央高校基本科研业务费专项资金（20720190036、20720160032）的资助与支持