A microwave-assisted strategy was developed for the synthesis of nitrogen and boron co-doped graphene (NB-G) with a hierarchical framework, and the NB-G was characterized by transmission electron microscopy, scanning electron microscopy, X-ray photoelectron spectroscopy and Raman spectroscopy. The resultant NB-G network provided multidimensional electron transport pathways, and was used in the electrocatalytic reduction for hydrogen peroxide (H 2 O 2 ) sensing, exhibiting an excellent response and stability. The NB-G modified electrochemical sensor showed a linear range from 0.5 mM to 5 mM with a detection limit of 0.05 mM at a signal-to-noise ratio of 3. This high performance was attributed to both the beneficial structure of NB-G and synergetic effects arising from the co-doping of N and B in graphene. The proposed biosensor was also used to achieve real-time quantitative detection of H 2 O 2 from living cells at the nanomolar level, which exhibited excellent electrochemical activity.

A metal-free and external oxidant-free method for the C-3 amination of 2H-indazoles in good yields was developed under electrochemical conditions.

The structures and reactivities of pseudoephedrine-derived dianionic Myers enolates are examined. A combination of NMR and IR spectroscopic, crystallographic, and computational data reveal that the homoaggregated dianions form octalithiated tetramers displaying S 4-symmetric Li 8 O 8 cores and overall C 2 symmetry. Computational and isotopic labeling studies reveal strong N-Li contacts in the carboxamide enolate moiety. The method of continuous variations proves deceptive, as octalithiated tetrameric homoaggregates afford hexalithiated trimeric heteroaggregates. A lithium diisopropylamide-lithium enolate mixed aggregate is found to be a C 2-symmetric hexalithiated species incorporating two enolate dianions and two lithium diisopropylamide (LDA) subunits. Structural and rate studies show that lithium chloride has little effect on the dynamics of the enolate homoaggregates but forms adducts of unknown structure. Rate studies of alkylations indicate that the aging of the aggregates can have effects spanning orders of magnitude. The LiClenolate adduct dramatically accelerates the reaction but requires superstoichiometric quantities owing to putative autoinhibition. Efforts and progress toward eliminating the requisite large excess of LiCl are discussed.

AbstractLight olefins such as ethylene, propylene and butylene are mainly used in the petrochemical industry. Due to the growing need for light olefins in the industry and the future shortage of petroleum resources, the process of converting methanol to olefins (MTO) using non-oil sources has been considered as an alternative. Coal and natural gas are abundant in nature and the methods of converting them to methanol are well known today. Coal gasification or steam reforming of natural gas to produce synthetic gas (CO and hydrogen gas) can lead to methanol production. Methanol can also be catalytically converted to gasoline or olefins depending on the effective process and catalyst factors used. Due to the use of crude methanol in the MTO unit and because the feed does not require primary distillation, if the MTO unit is installed alongside the methanol unit, its capital costs will be reduced. The use of methanol can have advantages such as easier and less expensive transportation than ethane. Among the available catalysts, SAPO-34 is the most suitable catalyst for this process due to its small cavities and medium acidity. One of the problems of MTO units is the rapid deactivation of SAPO-34, which can also be affected by the synthesis factors, so it is possible to optimize the catalyst performance by modifying the synthesis conditions. In this article, we will introduce the MTO process and the factors affecting the production of light olefins.