Nickel hydroxide armour promoted CoP nanowires for alkaline hydrogen evolution at large current density

The development of hydrogen evolution activity (HER) electrocatalyst that can run durably and efficiently under the large current density is of special significance but still challengeable for the massive production of hydrogen. Herein, a CoP/Ni(OH)₂ nanowire catalysts grown on Co foam (CF) with a three-dimensional heterojunction structure has been successfully prepared by electrodepositing nickel hydroxide on the surface of cobalt phosphide. The prepared CoP/Ni(OH)₂–15 min sample reveals a superior HER activity and stability. It merely requires ultralow overpotentials of 108 and 175 mV to 100 and 500 mA cm^?2, respectively. In addition, the long-term stability test shows that the catalyst (CoP/Ni(OH)₂–15 min) can operate stably for at least 70 h at 400 mA cm^?2. Utilizing NiFe-LDH/IF with high OER activity, the NiFe-LDH/IF || CoP/Ni(OH)₂–15 min catalyst system possesses the same outstanding performance for overall water splitting (OWS), which can accomplish ≈ 500 mA cm^?2 at 1.74 V in 1 M KOH electrolyte. Moreover, the NiFe-LDH/IF || CoP/Ni(OH)₂–15 min couple can work for more than 80 h at 500 mA cm^?2, indicating its a great prospect in the area of electrolysis water. Such excellent catalytic performance is mainly attributed to the armor effect of Ni(OH)₂, which can not only promote the rapid decomposition of water molecules, but also prevent the loss of phosphorus and enhance the synergistic effect of CoP and Ni(OH)₂. This work can offer a significant reference for the design with high-performance and durable transition metal phosphide electrocatalysts.     

Effects of microstructure shape parameters on water removal in a PEMFC lotus-like flow channel

To improve the drag reduction performances of the proton exchange membrane fuel cell (PEMFC), a three dimensional numerical investigation about the water removal in a lotus-like PEMFC flow channel is carried out. The effects of the microstructure shape parameters (height, radius and spacing) are investigated. The investigation revealed that the liquid water can be effectively removed by the lotus-like flow channel from the channel wall surface. The appropriate height of lotus-like channel can effectively reduce the water coverage ratio on the top wall of the lotus-like flow channel. As height increases, the average drag reduction ratio increases firstly and decreases finally. When the radiuses are 25 μm and 50 μm, the average drag reduction ratios of these cases are higher than those of the other cases obviously. The spacing of the lotus-like channel has a few effects on the water removal and water coverage ratio. The lotus-like flow channel with the height of 50 μm, the radius of 50 μm and the spacing of 150 μm has a high drag reduction and anti-corrosion performance. The work in this study provides a new choice for the flow channel and has certain guiding significance for the design of the flow channel for anti-corrosion and drag reduction.     

微波作用下硅藻土酸浸除铁过程研究

研究在微波作用下硅藻土酸浸除铁过程的影响因素和工艺条件。结果表明。硫酸浓度、微波功率和浸出时间对硅藻土除铁均有影响，浸出时间是影响浸出的最主要因素，微波功率和硫酸浓度次之。随浸出时间延长。微波功率增加，硫酸浓度加大，硅藻土中的Fe2O3含量减少。Fe2O3浸出率增加。在试验条件下。较佳的工艺条件为硫酸浓度40％，浸出时间45min，微波功率260W。在此条件下获得的硅藻土产品指标为SiO283．50％，Al2O37．18％，Fe2O30．87％，达到了硅藻土助滤剂质量标准SiO2〉80％，Al2O3〈10％。Fe2O3〈2％。     

天然气/液化气先进再燃脱硝特性研究

利用自行研制的可燃气体再燃脱硝实验台，在先进再燃脱硝的典型影响因素条件下比较了两种再燃燃料的脱硝特性.实验燃料先进再燃脱硝时均存在最佳过量空气系数、最佳NH₃/NO摩尔比；1 050,1 150 ℃时脱硝效率随再燃气/NO摩尔比增加而提高，而1 200 ℃时脱硝效率随天然气/NO比增加先升高后降低，实验最佳天然气/NO比为3.63；天然气/液化气先进再燃时再燃区最佳温度分别为1 250 ℃与1 050 ℃，再燃区温度高于1 150 ℃时选择天然气为再燃燃料，反之选择液化气；从停留时间上考虑应优先选择天然气作为再燃燃料.     

煤热解过程中氯的脱除研究

氯是煤中对环境有严重危害的微量有害元素之一。研究煤中氯的释放特性对于煤中氯的脱除和控制具有重要意义。文中测定了煤中氯在不同的煤热解温度下的脱除率，探讨了氯在热解过程中的析出规律。结果表明，煤中氯随温度的析出均符合S型函数关系；不同煤种，氯的析出温度区间不同；当热解温度为1000℃时，煤中氯基本脱除。     

酸法提取氧化铝工艺中除铁技术的研究进展

酸法提取氧化铝是从低品位铝土矿或高铝粉煤灰中提取氧化铝的重要方法之一,对解决我国铝土矿资源短缺,保障金属铝供应具有重要战略意义。从酸性浸出液中去除铁离子是酸法提取氧化铝成套技术中绕不过的重要环节,直接关系到氧化铝产品的质量。本文综述了酸法提取氧化铝工艺中除铁技术进展,重点对溶剂萃取法和树脂吸附法这两种在酸法提取氧化铝方面具有工业化应用前景的除铁技术研究进展进行了介绍,并对两种方法的优缺点以及适应性进行了分析,为酸法提取氧化铝工艺技术开发中除铁环节的技术选择提供参考。     

对武安高岭土除铁工艺研究

河北武安硬质高岭土粉含Fe2O31.23%，经高梯度磁选后降至0.77%，再用Na2S2O3进行还原溶解后降至0.62%，白度提高了13％，本文介绍了流程及条件试验过程和结果。     

沸石去除废水中氨氮的研究进展

沸石是一种天然的廉价矿物,对水中的氨氮具有较强的吸附作用,本文介绍了天然及改性沸石在去除水中氨氮的应用现状及进展,在此基础上提出了加强沸石在水处理领域研究力度、加大对资源开发的资金投入和加速成果转化的建议。     

微粉煤摩擦电选脱硫降灰试验研究

火电厂燃煤造成的SO2污染日益严重,应用摩擦电选技术,结合火电厂自身制粉系统的工艺特点进行燃前在线脱硫降灰是一项工艺合理、低成本的高效脱硫技术。文章对摩擦电选机操作参数对分选效果的影响进行了大量的试验研究。     

MGTY-300/710电牵引采煤机典型故障分析及处理

MGTY-300/710电牵引采煤机采用了变频调速与直接转矩控制技术,是一种新型的电牵引采煤机。结合生产实践中的故障案例分析了该采煤机电控系统的常见故障,并提出了相应的处理方法。