Influence of the Nb/P ratio of acidic Nb P Si oxides on surface and catalytic properties

Abstract

Highlights  A new Nb-P-Si gel derived catalyst with Nb/P=2 was prepared and its performances in the dehydration of fructose was tested and compared with those of Nb-P-Si gel derived catalyst with Nb/P=1.  The two Nb-P-Si gel derived catalysts maintained their effective acidity in both reaction environments, water and water-isopropanol solution, that directed the catalytic performances of activity and selectivity to hydroxymethylfurfural (HMF).  The catalysts durability and their selectivity to HMF were better in waterisopropanol solution than in water due to higher solubility of humins in the alcoholic solution.

Phosphate Enrichment of Niobium-Based Catalytic Surfaces in Relation to Reactions of Carbohydrate Biomass Conversion: The Case Studies of Inulin Hydrolysis and Fructose Dehydration

“…In fact, this second contribution was predominant in the NbP sample, and it gradually lowered and disappeared by decreasing P content in the samples. Oxygen signal in the 1s region was fitted with three components, located at 530.2, 531.1, and 532.4 eV associated with oxygen involved in the Nb-O and Nb-O-P bonds and in phosphate groups (O-P) [25]. Finally, the P 2p spectrum can be decomposed as a doublet having a spin-orbital split of ca.…”

Phosphorus‐Modified Mesoporous Inorganic Materials for Production of Hydrocarbon Fuels and Value‐Added Chemicals

“…The above results clearly indicated that the importance of the textural and acidic properties to achieve higher yields of the specific target products such as furfural, HMF and levulinic acid. Moreover, as shown below, the nature of calcination temperatures and pore sizes of the metal phosphates, pH, surface phosphate species, and type of surfactants on metal phosphates and carbohydrate sugars along with reaction parameters significantly altered both final target product yields and stability …”

“…Moreover, as shown below, the nature of calcination temperatures and pore sizes of the metal phosphates, pH, surface phosphate species, and type of surfactants on metal phosphates and carbohydrate sugars along with reaction parameters significantly altered both final target product yields and stability. [14,[82][83][84][85][86][87][88][89][90] Figure 6. Effects of B/L ratios to the catalytic performance in terms of furfural selectivity and initial reaction rate on mesoporous tantalum phosphates.…”

“…The formed stable phosphate units, cross-linked through Nb bridges in the silicate matrix (i. e., SiÀ OÀ NbÀ OÀ P), were responsible for higher acidic properties and catalytic conversion of fructose to HMF . [90] The natures of mesopore diameters as well as acid site densities with their strengths played an important role to determine overall catalytic activities during the catalytic biomass conversion. [14,83,84,91] For example, as shown in Scheme 2, Bhaumik et al [84,91] have prepared the selfaggregated large-pore mesoporous (10.4 nm) tin phosphate nanoparticles (LPSnP-1) with higher surface acidity of 2.2 mmol/ g, which utilized for conversion of wide-range of biomassderived feedstocks such as fructose, glucose, sucrose, cellobiose and cellulose into HMF in biphasic solvents media (water/ methyl isobutyl ketone (MIBK)) under microwave-assisted heating condition at 150°C.…”

“…The formed stable phosphate units, cross‐linked through Nb bridges in the silicate matrix (i. e., Si−O−Nb−O−P), were responsible for higher acidic properties and catalytic conversion of fructose to HMF . The natures of mesopore diameters as well as acid site densities with their strengths played an important role to determine overall catalytic activities during the catalytic biomass conversion . For example, as shown in Scheme , Bhaumik et al .…”