Octahedral Cu_2O-modified TiO_2 nanotube arrays for efficient photocatalytic reduction of CO_2

A photocatalyst composed of TiO 2 nanotube arrays（TNTs） and octahedral Cu2 O nanoparticles was fabricated,and its performance in the photocatalytic reduction of CO2 under visible and simulated solar irradiation was studied. The average nanotube diameter and length was 100 nm and 5 μm,respectively. The different amount of octahedral Cu2 O modified TNTs were obtained by varying electrochemical deposition time. TNTs modified with an optimized amount of Cu2 O nanoparticles exhibited high efficiency in the photocatalysis,and the predominant hydrocarbon product was methane. The methane yield increased with increasing Cu2 O content of the catalyst up to a certain deposition time,and decreased with further increase in Cu2 O deposition time. Insufficient deposition time（5 min） resulted in a small amount of Cu2 O nanoparticles on the TNTs,leading to the disadvantage of harvesting light. However,excess deposition time（45 min） gave rise to entire TNT surface being most covered with Cu2 O nanoparticles with large sizes,inconvenient for the transport of photo-generated carriers. The highest methane yield under simulated solar and visible light irradiation was observed for the catalysts prepared at a Cu2 O deposition time of 15 and 30 min respectively. The morphology,crystallization,photoresponse and electrochemical properties of the catalyst were characterized to understand the mechanism of its high photocatalytic activity. The TNT structure provided abundant active sites for the adsorption of reactants,and promoted the transport of photogenerated carriers that improved charge separation. Modifying the TNTs with octahedral Cu2 O nanoparticles promoted light absorption,and prevented the hydrocarbon product from oxidation. These factors provided the Cu2O-modified TNT photocatalyst with high efficiency in the reduction of CO2,without requiring co-catalysts or sacrificial agents.

Focus on the Chinese revolution of catalysis based on catalytic solutions for the vital demands of society and economy

Catalysis is one of the most cross-cutting technologies in the chemical industry, intensely influenc-ing our daily society. Its practical application is closely related to the engineering disciplines. At present, the academic and industrial research on catalysis in our country has made great break-throughs in fields like hydrocarbon production, oil-quality upgrading processes, green chemical engineering, and other energy and chemical users of catalysis. In this paper, we attempt to summa-rize the industrial catalysis achievements and present a discussion on the direction and the devel-opment strategy for catalysis, based on economic and social demands.

Turning the V site in V@2D-BC_(3)N_(2)complex to high curvature state for efficient CO_(2)electroreduction to hydrocarbons

Hydrocarbons are promising products for CO_(2)electroreduction(CRR)while is impeded by the low selectivity.Turning the curvature of the active site is an effective strategy to change the adsorption properties and further regulate the product distribution and reactivity.Herein,we have designed a novel V single atom catalyst(SAC)based on rolled two-dimensional(2D)BC_(3)N_(2)substrate with different curvatures.The results have demonstrated that increased curvature can enhance the adsorption strength of CRR intermediates,which follows different mechanisms for systems with low and high curvature.This character eventually leads to the deviation away from the scaling line between Ead[CO]∼Ead[COOH]based on transition metals for V@2D-BC_(3)N_(2)systems.3-3 system is screened as the optimal candidate for hydrocarbons production due to the enhanced binding ability of adsorbates,which can increase the reactivity for hydrocarbons production and hinder the production of H2 and HCOOH simultaneously.

In-situ FTIR studies of dimethyl ether adsorption on H-ZSM-5 zeolites

In situ infrared spectra of dimethyl ether adsorbed on two H-ZSM-5 zeolites are reported which are different in both lattice and extraframework aluminium contents. A number of dissociatively adsorbed dimethyl ether species associated respectively with the Bronsted acid sites, the external silanol groups and extraframework aluminium species at different temperatures are identified. In particular, dimethyl ether reacts with non acidic hydroxyl species associated with extraframework aluminium to form the third methoxy species. The distributions of hydrocarbons desorbed from a single pulse of dimethyl ether (1.0 mL) onto these zeolite samples are presented. Propene is the major product, and the yield of hydrocarbons correlates with the concentration of Bronsted acid bound methoxy groups.

Optimal field development and production design for unconventional reservoirs:A case study from Central Sub-Basin,Permian Basin,New Mexico

The planning and developmental decisions succeeding the discovery of an unconventional oil and gas field is of utmost importance in attaining successful exploitation and production from these tight reservoirs.The development and production of hydrocarbon from these unconventional reservoirs require requires adequate planning and execution which could be challenging,due to the sequence of heterogeneous lithologies of these formations.In this study,we designed and presented a comprehensive field development and production program that is representative of the unconventional oil and gas development in the Central sub-basin of the Permian Basin.To design and achieve optimal field development and production for unconventional reservoirs in the Central sub-basin of the Permian Basin,New Mexico,we utilized field data from an oil and gas well that was drilled to a TVD/MD of 2290 m with a PBTD of 2270 m.Subsequently,we conducted the petrophysical evaluation of the logs and utilized a decline curve analysis for reservoir evaluation of all the members of the formation.We also designed and developed comprehensive drilling,completions,and facilities programs.Lastly,we incorporated an economic analysis of our optimized field development and production design.Our results provide a valuable plan and critical decision-making insight for optimizing field development and production of unconventional reservoirs in the Permian Basin and across the world.