Electrochemistry represents a powerful sustainable method for chemical synthesis; however, its widespread application is limited due to the lack of exposure and appropriate basic training of synthetic chemists and engineers in electrochemistry and electrochemical engineering. The introduction of diverse laboratory practices to the current curricula will improve the understanding of electrochemistry and the theory behind its various applications. Here, we suggest an efficient laboratory experiment on the electrochemical reduction of CO 2 to CO using inexpensive and readily available materials, such as metal wires, plastic vessels, batteries, and a handheld CO detector. Students learn to assemble a divided electrochemical cell and perform important electrochemical reactions, such as electrochemical CO 2 reduction and hydrogen evolution reaction.In this experiment, students analyze the rates of CO production under different electrolysis conditions and learn to understand the effects of operating parameters (applied potential, electrolyte concentration, and nature of the electrode) on the outcome of the reaction. This new comprehensive laboratory experiment is designed for students to better understand basic principles of electrochemistry and is suitable for undergraduate students.

We present a sacrificial anode-free approach to reductive homocoupling of organohalides that does not require a co-catalyst. In this approach, a divided electrochemical cell with aprotic and aqueous compartments separated by an anion exchange membrane enables coupling of the cathodic homocoupling reaction with anodic oxidation of urea. We show that, in contrast with traditional one-compartment cells relying on sacrificial anodes, the proposed cell configuration maintains stable cell voltage in the course of galvanostatic electrolysis. A synthetic potential of this method was assessed using a series of 13 organic bromides that demonstrated a strong dependence of the reaction outcome on the structure of the organic substrate, more specifically, the dissociation energy of the C–Br bond and the redox properties of formed radicals, which are discussed in detail. While not being suitable for the synthesis of byarylstructures, this method is excellent for C(sp3)-C(sp3) coupling to corresponding dimeric products with up to quantitative yields. Simultaneous electrochemical treatment of nitrogenous waste in the adjacent half-cell provides an additional incentive for wide adaptation of this sustainable synthetic approach.

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The article describes the synthesis of highly dispersed powder of chromium diboride CrB 2 using nanofiber carbon in the process of boron carbide reduction. This compound is a refractory material with melting point of 2200°С. Due to its chemical and physical properties, chromium diboride is widely used in different fields of industry. Chromium oxide (III) Cr 2 O 3 , boron carbide B 4 C and nanofiber carbon C were used as initial reagents. The synthesis was conducted by the use of an induction furnace of a melting pot type in a protective atmosphere of argon at temperatures of 1300, 1500 and 1700°С. Using X-ray phase analysis, atomic emission spectroscopy with inductively coupled plasma, scanning electron microscopy and synchronized thermal TG-DSC analysis general properties and characteristics of the materials obtained were determined. Particle size distribution studies have been also carried out and it has been found that the average size of chromium diboride powder was 7.95 µm. It has been found that the sample of chromium diboride obtained resists oxidation under higher temperatures (1000°С). The paper also deals with the problem of targeted planning of chromium diboride synthesis depending on different experimental conditions. By the use of targeted experiment planning method, the effects of such parameters as synthesis temperature, time of stirring of the initial batch, as well as carbon reducing agent which significantly affects the synthesis process were estimated. It has been found that optimum synthesis conditions consist in an activation of batch in a ball mill with acceleration of 10g for 5 minutes and a synthesis at 1700°С for 20 minutes. В данной работе описан процесс получения высокодисперсного порошка диборида хрома CrB 2 с использованием нановолокнистого углерода карбидоборным методом. Данное соединение является тугоплавким, его температура плавления составляет 2200°С. За счет своих физико-химических свойств диборид хрома получил широкое приме-нение в промышленности. В качестве исходных реагентов использовали оксид хрома (III) Cr 2 O 3 , карбид бора B 4 C и нановолокнистый углерод С. Синтез проводили в индукционной печи тигельного типа в защитной среде аргона при температурах 1300, 1500 и 1700°С. С помощью методов рентгенофазового анализа, атомно-эмиссионной спек-троскопии с индуктивно связанной плазмой, растровой электронной микроскопии, синхронного термического ТГ-ДСК-анализа определили основные свойства и характеристики полученных образцов. Выполнены грануломе-трические исследования, в ходе которых определили средний размер частиц полученного порошка диборида хрома, который составил 7,95 мкм. Установлено, что полученный образец диборида хрома эффективно сопротивляется окислению при повышенных температурах (1000°С). Также в данной статье рассмотрены вопросы направленного планирования процесса синтеза диборида хрома в зависимости от различных условий проведения эксперимента. Методом направленного планирования эксперимента было оценено влияние на процесс синтеза таких параметров, как температура с...