The Effect of Ni-ZSM-5 Catalysts on Catalytic Pyrolysis and Hydro-Pyrolysis of Biomass.

With the demand of energy and re-utilization of wastes, the renewable lignocellulosic biomass, has attracted increasing and significant attention for alleviating the growing energy crisis and environment problems. As main components of lignocellulosic biomass, lignin, cellulose, and hemicellulose are connected by hydrogen bond to form a compact skeleton structure, resulting the trenchant condition of biomass pyrolysis. Also, pyrolysis products of above three main constituents contain a large amount of oxygenates that cause low heating value, high corrosiveness, high viscosity, and instability. Meanwhile, zeolites are of considerable significance to the conversion of lignocellulosic biomass to desirable chemical products on account of fine shape selectivity and moderate acid sites and strength. Among numerous zeolites, ZSM-5-based catalysts have been most extensively studied, and the acidity and porosity of ZSM-5 can be tuned by changing the content of Si or Al in zeolite. Beyond that, doping of other metal elements, such as Mn, Co, Ni, Ga, Ce, Pt, into ZSM-5 is also an efficient way to regulate the strength and density of acid sites in zeolite precisely. This review focused on the recent investigation of Ni-modified microporous ZSM-5 used in catalytic pyrolysis of lignin and cellulose. The application of metal-modified hierarchical ZSM-5 is also covered.

Solvothermal Synthesis of Humic Acid-Supported CeO2 Nanosheets Composite as High Performance Adsorbent for Congo Red Removal.

Surface properties and structures of materials are essential for their adsorption of pollutants in water. Humic acids (HA)-supported CeO2 nanosheet composites are synthesised by solvothermal method. The size of CeO2 nanosheets are approximately 100-500 nm. The obtained composite exhibits superior adsorption ability for Congo Red (CR) in water, which can be attributed to its unique structure and highly dispersed CeO2 nanosheet. The composite's adsorption behaviour of CR follows a pseudo-second-order mode and Langmuir adsorption model well, and the maximum adsorptive capacity for CR achieves 260 mg g-1. The presence of CeO2 nanosheets enhances surface area and enriches the mesoporous structure of the composites, thereby promoting CR adsorption capacity.

Indented Cu2MoS4 nanosheets with enhanced electrocatalytic and photocatalytic activities realized through edge engineering.

Edges often play a role as active centers for catalytic reactions in some nanomaterials. Therefore it is highly desirable to enhance catalytic activity of a material through modulating the microstructure of the edges. However, the study associated with edge engineering is less investigated and still at its preliminary stage. Here we report that Cu2MoS4 nanosheets with indented edges can be fabricated through a simple chemical etching route at room temperature, using Cu2MoS4 nanosheets with flat ones as sacrifice templates. Taking the electrocatalytic hydrogen evolution reaction (HER), photocatalytic degradation of rhodamine B (RhB) and conversion of benzyl alcohol as examples, the catalytic activity of Cu2MoS4 indented nanosheets (INSs) obtained through edge engineering was comparatively studied with those of Cu2MoS4 flat nanosheets (FNSs) without any modification. The photocatalytic tests revealed that the catalytic active sites of Cu2MoS4 nanosheets were associated with their edges rather than basal planes. Cu2MoS4 INSs were endowed with larger electrochemically active surface area (ECSA), more active edges and better hydrophilicity through the edge engineering. As a result, the as-fabricated Cu2MoS4 INSs exhibited an excellent HER activity with a small Tafel slope of 77 mV dec(-1), which is among the best records for Cu2MoS4 catalysts. The present work demonstrated the validity of adjusting catalytic activity of the material through edge engineering and provided a new strategy for designing and developing highly efficient catalysts.