An Overview of Recent Developments in Hetero-Catalytic Conversion of Cellulosic Biomass

In recent years, research activities involved in the production of nanocellulosic materials have grown substantially, rapidly stimulating the development of innovative production techniques. These materials are chemically extracted by acid-catalyzed Hydrolysis of the renewable and widely available cellulosic biomass. In this regard, sulfuric acid-catalyzed Hydrolysis of cellulosic biomass is a commonly known method for the production of nanostructured cellulose. However, this method may result in many disadvantages, including short catalyst-lifetime, corrosive to the reactor materials and managing the spent sulfuric acid resulted from the production process. This dictates the implementation of an eco-industrial alternative for the catalytic production of nanocrystalline cellulose (NCC). A viable and practical alternative is the application of heterogeneous (solid acids) catalysts, which can be more conducive in providing favorable platforms for efficient cellulose hydrolysis. This review highlights the current production methods of nanocrystalline cellulose. Further, recent literature on the heterogeneous-catalytic conversion of cellulosic biomass is briefly discussed. The limitations and disadvantages of these techniques are also described.

Influence of intimacy for metal-mesoporous solid acids catalysts for n-alkanes hydro-conversion

Pt on both ordered mesoporous Al-SBA-15 and commercial amorphous mesoporous silica–alumina bi-functional catalysts were prepared and studied for n-heptane hydro-isomerization and n-hexadecane hydro-cracking.

A comparative study of n-hexane isomerization over solid acids catalysts: Sulfated and phosphated zirconia

Two series of zirconia based catalysts promoted with either sulfates or phosphates were prepared, calcined at different temperatures (600 and 700?C) and evaluated for the n-hexane isomerization reaction. The catalysts with different concentrations of sulfates or phosphates (4 or 10 wt. %) were characterized by BET, XRD, SEM methods, and total acidity was evaluated by using the Hammett indicators. Their final catalytic performances were correlated with their physical-chemical properties (surface, structural, textural and morphological). It was found that sulfated zirconia catalyst calcined at lower temperature showed the highest initial activity of all tested catalysts as the result of favorable total acidity, mesopore texture and structural properties. Somewhat lower activity of the sulfated catalyst calcined at higher temperature is related to the content of acid groups partially removed during thermal treatment, thus, lower total acidity, and also to less favorable textural and structural features. Negligible activity of phosphated zirconia catalysts is connected with low total acidity despite the positive status of particular property showing the complexity of the active phase/site formation in the catalyst.