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H_2 generation kinetics/thermodynamics and hydrolysis mechanism of high-performance La-doped Mg-Ni alloys in Na Cl solution——A large-scale and quick strategy to get hydrogen

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Journal of Magnesium and Alloys 2021年第3期9卷 1068-1083页

作者： Xiaojiang Hou Hongchang Shi Lu Yang Kaiming Hou Yi Wang Lei Feng Guoquan Suo Xiaohui Ye Li Zhang Yanling Yang School of Material Science and Engineering Shaanxi Key Laboratory of Green Preparation and Functionalization for Inorganic MaterialsShaanxi University of Science and TechnologyXi'an 710021China State Key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi'an 710072China

In this work,La-doped Mg-Ni multiphase alloys were prepared by resistance melting furnace(RMF)and then modified by high-energy ball milling(HEBM).The hydrolysis H_(2) generation kinetics/thermodynamics of prepared alloys in Na Cl solutions have been investigated with the help of nonlinear and linear fitting by Avrami-Erofeev and Arrhenius *** the microstructure information before and after hydrolysis and thermodynamics fitting results,the hydrolysis H_(2) generation mechanism based on nucleation&growth has been *** final H_(2) generation capacities of 0La,5La,10La and 15 La alloys are 677,653,641 and 770 m L·g^(-1)H_(2) in 240 min at291 K,***,the final H_(2) generation capacities of HEBM 0La,5La,10La and 15 La alloys are 632,824,611 and 653 m L·g^(-1)H_(2) in 20 min at 291 K,*** as-cast 15La alloy and HEMB 5La alloy present the best H_(2) production rates and final H_(2) production capacities,especially the HEBM 5La can rapidly achieve high H_(2) generation capacity(670 and 824 m L·g^(-1)H_(2) )at low temperature(291 K)within short time(5 and 20 min).The difference between the H_(2) generation capacities is mainly originated from the initial nucleation rate of Mg(OH)_(2) and the subsequent processes affected by the microstructures and phase compositions of the hydrolysis *** low initial nucleation rate and fully growth of Mg(OH)_(2) nucleus are the premise of high H_(2) generation capacity due to the hydrolysis H_(2) generation process consisted by the nucleation,growth and contacting of Mg(OH)_(2) *** utilization H_(2) by designing solid state H_(2) generators using optimized Mg-based alloys is expected to be a feasible H_(2) generation strategy at the moment.

关键词： H_(2)generation La-doped Mg-Ni alloys Kinetics Thermodynamics hydrolysis mechanism

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Carbon dots-confined CoP-CoO nanoheterostructure with strong interfacial synergy triggered the robust hydrogen evolution from ammonia borane

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Journal of Energy Chemistry 2021年第6期30卷 198-205,I0006页

作者： Han Wu Yaojia Cheng Boyang Wang Yao Wang Min Wu Weidong Li Baozhong Liu Siyu Lu College of Chemistry and Institute of Green CatalysisZhengzhou UniversityZhengzhou 450001HenanChina College of Chemistry and Chemical Engineering Henan Polytechnic UniversityJiaozuo 454000HenanChina Guangdong Provincial Key Laboratory of Optical Information Materials and Technology Guangzhou 510631GuangdongChina College of Materials Science and Engineering Zhejiang University of TechnologyHangzhou 310014ZhejiangChina

Ammonia borane(NH_(3)BH_(3),AB) is promising for chemical hydrogen sto rage;however,current systems for rapid hydrogen production are limited by the expensive noble metal catalysts required for AB *** we report the design and synthesis of a highly efficient and robust non-noble-metal catalyst for the hydrolysis of AB at 298 K(TOF=89.56 molH_(2) min^(-1) molCo^(-1)).Experiments and density functional theory calculations were performed to explore the catalyst’s hybrid nanoparticle heterostructure and its catalytic *** catalyst comprised nitrogen-doped carbon dots confining CoO and CoP,and exhibited strong interface-induced synergistic catalysis for AB hydrolysis that effectively decreased the energy barriers for the dissociation of both AB and water *** co-doping of N and P introduced numerous defects,and further regulated the reactivity of the carbon *** heterogeneous interface design technique presented here provides a new strategy for developing efficient and inexpensive non-noblemetal catalysts that may be applicable in other fields related to energy catalysis.

关键词： Nano-heterostructure Interface engineering Ammonia borane hydrolysis mechanism Hydrogen

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DFT Study on the Roles of Calcium and Its Coordination Variation Play in the mechanism of Diisopropyl Fluorophosphatase

DFT Study on the Roles of Calcium and Its Coordination Varia...

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中国化学会第30届学术年会-第十九分会：化学中的量子与经典动力学

作者： Ling Yang W.Tian R.-Z.Liao Institute of Theoretical and Simulation Chemistry School of Chemistry and Chemical Engineering Harbin Institute of Technology School of Chemistry and Chemical Engineering Huazhong University of Science and Technology

Catalytic mechanism of diisopropyl fluorophosphatase from Loligo vulgaris is investigated using the hybrid density functional theory method B3LYP with a large quantum chemical model of the active site. For the first step, both Asp229 and an activated water molecule are capable of proceeding in-line attack on the substrate with the associated barriers 14.8 and 6.0 kcal/mol, respectively. Asp229 plays a dual role during the two reaction processes as either a nucleophile or a general base to activate HO. From the phosphoenzyme intermediate with hexa-coordinated Ca, the uncoordinated Glu21 activated an additional HO to attack the carbon center of Asp229 and make the phosphate release. Asn120 and Asn175 promote the elimination of the fluoride via donating strong hydrogen bonds. Coordination variation of calcium plays important role of the enzymatic reaction to occur. The calculated detailed reaction mechanisms will promote the structure-based protein engineering to modify hydrolysis rates and substrate specific.

关键词： Enzymatic reaction hydrolysis mechanism Density functional calculations

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Re-examination of the Hydration of Carbon Dioxide in the Neutral Water:A Comprehensive Computational Study

Re-examination of the Hydration of Carbon Dioxide in the Neu...

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第九届全国计算（机）化学学术会议

作者： Chao Deng Yi Ren College of Chemistry,Center of Computational Chemistry and Biology and Key State Laboratory of Biotherapy,Sichuan University,Chengdu 610064,China,

The detailed reaction mechanism of the catalyzed hydration of carbon dioxide by water and water clusters has been re-examined theoretically at the level of HF and MP2 with the basis set of 6-311++Gin the presence of up to five water molecules[CO+nHO→HCO+(n-1) HO,n=1-5].The activation barriers,ΔH(?),for the rate-determining steps of one up to five-water hydrolyses of carbon dioxide,are 222.0,149.0,124.7,112.8 and 90.5 kJ/mol in the gas phase,*** most favorable hydrolysis path of CO involves a sort of eight-membered ring transition structure and other two water molecules near to the nonreactive oxygen atom but not involved in the proton transfer,suggesting that the hydrolysis of CO can be significantly mediated by the water molecule(s)and the cooperative effects of the water molecule(s)in the nonreactive *** catalytic effect of water molecule(s)due to the alleviation of ring strain in the proton transfer process may results from the synergistic effects of rehybridization and charge reorganization from the pre-coordination complex to the rate-determining transition state structure induced by water molecule(s).PCM solvation models do not modify the calculated energy barriers in a significant *** calculated activation free energy for the hydrolysis of CO2 in the neutral water is 100.6 kJ/mol after PCM correction,which is closer to the available experimental date than the previous calculated results.

关键词： carbon dioxide hydrolysis mechanism natural population analysis

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