Chemistry methods : new approaches to solving problems in chemistry最新文献_第3页

Decoding Voltammograms at the Molecular Frontier: Integration of Voltammetry and Mass Spectrometry 分子前沿的伏安图解码：伏安法与质谱法的整合

IF 6.1

Chemistry methods : new approaches to solving problems in chemistry Pub Date : 2024-04-04 DOI: 10.1002/cmtd.202400003

Adarsh Koovakattil Surendran, Jana Roithová

{"title":"Decoding Voltammograms at the Molecular Frontier: Integration of Voltammetry and Mass Spectrometry","authors":"Adarsh Koovakattil Surendran, Jana Roithová","doi":"10.1002/cmtd.202400003","DOIUrl":"10.1002/cmtd.202400003","url":null,"abstract":"Electrochemical reactions are better understood by gaining insight into the molecular transformations at the electrodes. This paper introduces a straightforward experimental arrangement in which the voltammetry experiment in a standard electrochemical cell integrates with online electrospray-ionization mass-spectrometry. The procedure allows for monitoring of the ions produced at the working electrode. The ionic species sampling is facilitated by a silica capillary embedded in the working electrode and connected directly to the electrospray ionization source. This integration configures real-time monitoring of the ions produced at the working electrode, enhancing our knowledge of the electrochemical process. The methodology is thoroughly described and exemplified by monitoring the reactive intermediates and products that arise during the electrochemical oxidation of carbazole. This design provides an opportunity to study intermediates in electrochemical reactions with advanced mass spectrometry methods such as ion mobility separation or ion spectroscopy.","PeriodicalId":72562,"journal":{"name":"Chemistry methods : new approaches to solving problems in chemistry","volume":"4 6","pages":""},"PeriodicalIF":6.1,"publicationDate":"2024-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/cmtd.202400003","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140742907","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

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Cover Picture: (Chem. Methods 3/2024) 封面图片：（化学方法 3/2024）

Chemistry methods : new approaches to solving problems in chemistry Pub Date : 2024-03-08 DOI: 10.1002/cmtd.202480301

引用次数: 0

Non-Conventional Methodologies for the Synthesis of N-Nitrosamines 合成 N-亚硝胺的非常规方法

Chemistry methods : new approaches to solving problems in chemistry Pub Date : 2024-03-04 DOI: 10.1002/cmtd.202300053

Rojan Ali, Campbell S. Wolfe, Prof. Thomas Wirth

引用次数: 0

Thermal Elimination of Pyridine from a Uranium Trichloride Precursor 热消除三氯化铀前体中的吡啶

Chemistry methods : new approaches to solving problems in chemistry Pub Date : 2024-03-01 DOI: 10.1002/cmtd.202300052

Dr. Karla A. Erickson, Dr. Stephen S. Parker, Dr. Marisa J. Monreal

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Chemogenetic Tools in Focus: Proximity, Conformation, and Sterics 聚焦化学遗传工具：邻近性、构象和立体性

IF 6.1

Chemistry methods : new approaches to solving problems in chemistry Pub Date : 2024-02-29 DOI: 10.1002/cmtd.202300051

Dr. Jiaqi Shen, Guanwei Zhou, Prof. Dr. Wenjing Wang

引用次数: 0

Cover Picture: (Chem. Methods 2/2024) 封面图片：（化学方法 2/2024）

Chemistry methods : new approaches to solving problems in chemistry Pub Date : 2024-02-08 DOI: 10.1002/cmtd.202480201

引用次数: 0

Versatile Spectroscopic Cell for Operando Studies in Heterogeneous Catalysis Using Tender X-ray Spectroscopy in Fluorescence Mode 利用荧光模式下的嫩 X 射线光谱进行异相催化操作研究的多功能光谱池

Chemistry methods : new approaches to solving problems in chemistry Pub Date : 2024-01-16 DOI: 10.1002/cmtd.202300044

H. A. Suarez Orduz, S.-L. Heck, Dr. P. Dolcet, Dr. Y. Watier, Dr. M. Casapu, Prof. Dr. J.-D. Grunwaldt, Dr. P. Glatzel

{"title":"Versatile Spectroscopic Cell for Operando Studies in Heterogeneous Catalysis Using Tender X-ray Spectroscopy in Fluorescence Mode","authors":"H. A. Suarez Orduz, S.-L. Heck, Dr. P. Dolcet, Dr. Y. Watier, Dr. M. Casapu, Prof. Dr. J.-D. Grunwaldt, Dr. P. Glatzel","doi":"10.1002/cmtd.202300044","DOIUrl":"10.1002/cmtd.202300044","url":null,"abstract":"The design and commissioning of a cell suitable for operando studies using high-energy-resolution fluorescence-detected X-ray absorption near-edge structure (HERFD-XANES) spectroscopy in the tender X-ray regime is reported. The cell is optimized for measurements within the energy range of 1.5 keV to 4.5 keV. It has a plug-flow geometry and can be used for sieved powder samples, analogous to reactors employed for laboratory tests. The functionality of the spectroscopic cell is demonstrated in the area of emission control using CO oxidation as target reaction over 1 wt.% Rh/γ-Al2O3 as catalyst. We show how HERFD-XANES at the Rh L3-edge captures variations in the noble metal structure resulting from the interaction with the support material and reactant molecules. Moreover, distinct structural changes were identified along the catalyst bed as a function of temperature and local gas mixture.","PeriodicalId":72562,"journal":{"name":"Chemistry methods : new approaches to solving problems in chemistry","volume":"4 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/cmtd.202300044","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139618687","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Impedance Response Analysis of Anion Exchange Membrane Electrolyzers for Determination of the Electrochemically Active Catalyst Surface Area 用于确定电化学活性催化剂表面积的阴离子交换膜电解器阻抗响应分析

Chemistry methods : new approaches to solving problems in chemistry Pub Date : 2024-01-12 DOI: 10.1002/cmtd.202300035

Dr. Sebastian A. Watzele, Dr. Regina M. Kluge, Dr. Artjom Maljusch, Patrick Borowski, Prof. Dr. Aliaksandr S. Bandarenka

{"title":"Impedance Response Analysis of Anion Exchange Membrane Electrolyzers for Determination of the Electrochemically Active Catalyst Surface Area","authors":"Dr. Sebastian A. Watzele, Dr. Regina M. Kluge, Dr. Artjom Maljusch, Patrick Borowski, Prof. Dr. Aliaksandr S. Bandarenka","doi":"10.1002/cmtd.202300035","DOIUrl":"10.1002/cmtd.202300035","url":null,"abstract":"Polymer membrane electrolyzers benefit from high-pressure operation conditions and low gas cross-over and can either conduct protons (H+) or hydroxide ions (OH−). Both types of electrolyzers have a similar design, but differ in power density and the choice of catalysts. Despite the significant endeavor of their optimization, to date, there is no well-established impedance model for detailed analysis for either type of these devices. This complicates the in-situ characterization of electrolyzers, hindering the investigation of degradation mechanisms and electrocatalytic processes as a function of applied current density or time. Nevertheless, a detailed understanding of such individual processes and distinguishing the performance-limiting factors are the keystones for sophisticated device optimization. In this work, an impedance model based on electrode processes has been developed for an anion exchange membrane electrolyzer utilizing iridium oxide anode and platinum cathode electrocatalysts. This model allows to deconvolute the measured impedances into constituents related to the individual electrode processes and to estimate actual physico-chemical quantities such as the reaction kinetic parameters and double-layer capacitances. We discuss the meaning of the fitting parameters and show that this model enables, for the first time, the estimation of the electrochemically active surface area of the anode electrocatalysts under reaction conditions.","PeriodicalId":72562,"journal":{"name":"Chemistry methods : new approaches to solving problems in chemistry","volume":"4 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/cmtd.202300035","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139623695","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Cover Picture: (Chem. Methods 1/2024) 封面图片：（化学方法 1/2024）

Chemistry methods : new approaches to solving problems in chemistry Pub Date : 2024-01-08 DOI: 10.1002/cmtd.202480101

引用次数: 0

pHbot: Self-Driven Robot for pH Adjustment of Viscous Formulations via Physics-informed-ML** pHbot：通过物理信息ML**实现粘性配方 pH 值调节的自驱动机器人

Chemistry methods : new approaches to solving problems in chemistry Pub Date : 2023-12-13 DOI: 10.1002/cmtd.202300043

Aniket Chitre, Dr. Jayce Cheng, Sarfaraz Ahamed, Robert C. M. Querimit, Dr. Benchuan Zhu, Dr. Ke Wang, Dr. Long Wang, Prof. Kedar Hippalgaonkar, Prof. Alexei A. Lapkin

{"title":"pHbot: Self-Driven Robot for pH Adjustment of Viscous Formulations via Physics-informed-ML**","authors":"Aniket Chitre, Dr. Jayce Cheng, Sarfaraz Ahamed, Robert C. M. Querimit, Dr. Benchuan Zhu, Dr. Ke Wang, Dr. Long Wang, Prof. Kedar Hippalgaonkar, Prof. Alexei A. Lapkin","doi":"10.1002/cmtd.202300043","DOIUrl":"10.1002/cmtd.202300043","url":null,"abstract":"pH adjustment is crucial for many industrial products, yet this step is typically performed by manual trial-and-error. A particularly industrially relevant yet challenging titration is that of adjusting viscous liquid formulations using weak, polyprotic titrants (usually citric acid). Handling of viscous, non-Newtonian formulations, with such polyprotic acids preferred for their chelation and buffering effects make a robotic solution challenging. We present a self-driving pH robot integrated with physics-informed learning; this hybrid physical-ML model enables automated titration with weak-strong acid/base pairs. To deal with the high viscosities of these formulations, we developed specific automated mixing and cleaning protocols. We hit the target pH within two to five iterations over 250 distinct formulations in lab-scale small-batch (~10 mL and 12 samples) titrations. In the interest of scaling up to match industrial processes, we also demonstrate that our hybrid algorithm works at ~25× scale-up. The method is general, and we open-source our algorithm and designs.","PeriodicalId":72562,"journal":{"name":"Chemistry methods : new approaches to solving problems in chemistry","volume":"4 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/cmtd.202300043","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139181006","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0