Ultrafine Ru species within confined space: An efficient adsorbent for ultra-deep desulfurization of benzene.

The ultra-deep adsorptive desulfurization (ppb level) of benzene remains a challenging subject with the need to construct efficient adsorbent systems. Herein, a kind of ruthenium-based adsorbent functionalized with bimetallic Ru-Al was rationally designed using Al2O3 as support (denoted as 0.8%Ru-1.2%Al/Al2O3). It was found that the co-anchoring of Ru and Al species endows the Ru-based adsorbent unique adsorption capability, which is able to completely eliminate sulfur compounds in benzene, and exhibiting a much higher breakthrough sulfur capacity than that of the 0.8%Ru/Al2O3. Remarkably, under the industrial experiment conditions, 0.8%Ru-1.2%Al/Al2O3 exhibited excellent long-term stability for more than 1200 h, showing the potential for industrial application. Various characterization techniques, including BET, XRD, SEM, TEM, TPD-MS, TPR and XPS, were used to investigate the correlation between the adsorption performance and the microstructure of the adsorbents. Over 0.8%Ru-1.2%Al/Al2O3, the ultra-thin aluminum additive is beneficial to improve the dispersion of Ru species, which therefore exhibits desirable desulfurization efficiency. Moreover, the enhanced performance is also correlated to the presence of the suitable Ru active centers generated from the selective coverage by Al species. It leads to an optimal exposure of the Ru active centers, which would facilitate the interaction of S-Ru and the improvement of the desulfurization activity.

High-performance palladium catalysts for the hydrogenation toward dibenzylbiotinmethylester: Effect of carbon support functionalization.

Different functionalized carbon materials were used as supports to prepare Pd/carbon catalysts (Pd/AC, Pd/AC-O, Pd/AC-Cl and Pd/AC-N). The results of various characterization techniques revealed that a substantial increase in the surface functional groups of the supports could influence the size of the Pd nanoparticles and the chemical states of the Pd species due to Pd-support interactions. During the hydrogenation reaction to synthesize dibenzylbiotinmethylester, the Pd/AC-N catalyst, based on a support that was treated with nitric acid (AC-N), provided a higher yield of dibenzylbiotinmethylester than the other catalysts. The increase in surface oxygen groups (mainly CO2-releasing groups) in the AC-N support was relevant to achieving selective hydrogenation. These groups can provide an efficient pathway for the reaction, which may be responsible for the high yield of dibenzylbiotinmethylester.

N-doped nanoporous carbon as efficient catalyst for nitrobenzene reduction in sulfide-containing aqueous solutions.

Metal-free N-doped porous carbon (NC) materials have been demonstrated to be promising catalysts in contaminated environment remediation. Two NC materials (NC-1 and NC-2) were prepared by sol-gel routes. Their catalytic properties were investigated for the reduction of nitrobenzene (NB) in sulfide-containing aqueous solution. Both NC-1 and NC-2 can efficiently catalyze the reduction of NB to aniline (AN) under ambient conditions, but also can be reused for more than 5 times. The reaction fits excellently to the pseudo-first-order kinetic. Compared with NC-1 material, NC-2 shows much higher removal efficiency (rate constant kobs: 0.283h-1vs. 2.50h-1). The important features of NC material, including high specific surface area, suitable surface functional groups (especially nitrogen-containing groups), and enhanced electron transfer ability, should be mainly factors for its excellent catalytic activity. This work demonstrates that N-doped carbon materials have great potential for degradation of NB to AN in the natural aquatic environment.

Design and preparation of a simple and effective palladium catalyst and the hydrogenation performance toward dibenzylbiotinmethylester.

A series of well-dispersed carbon supported Pd catalysts were prepared by a simple and effective method under mild conditions. The functionalized carbon supported Pd catalyst (Pd/AC-H) demonstrated a enhanced performance to original carbon supported Pd catalyst (Pd/AC) in the probe reaction hydrogenation of 3,4-(1',3'-Dibenzyl-2'-oxoimidazolido)-2-(4-carboxybutylidene)thiophane to dibenzylbiotinmethylester. The results of various characterization techniques revealed that the improvement of Pd dispersion on Pd/AC-H catalyst surface could be associated to the presence of abundant oxygen-containing groups available for anchorage. Furthermore, the role of the surface groups of carbon supports was indispensable since they could provide an efficient pathway for the reaction. The oxygen-containing groups located at the Pd-supports interface were able to adjust the strength of reactant adsorption/activation on the Pd active sites, which was responsible for the high yield of dibenzylbiotinmethylester.

Adsorption behaviors of methyl orange dye on nitrogen-doped mesoporous carbon materials.

A series of nitrogen-doped mesoporous carbon materials (NMC) with different nitrogen contents (from 9.1 to 11.3 wt.%) were prepared using urea and ammonia as economical nitrogen resources by sol-gel method. The NMC materials possessed high surface areas (from 659 m(2)/g to 912 m(2)/g) as well as large number of oxygen-containing and nitrogen-containing groups. The adsorption behaviors of NMC materials for anionic dye methyl orange (MO) were investigated, which are fit excellent for the Langmuir isothermal adsorption equation. All the materials exhibited high adsorption capacity for MO at room temperature. Their adsorption capacity can be adjusted by changing the nitrogen contents in NMC materials. Moreover, treating the NMC material at higher temperature can significantly improve the adsorption capacity for MO. According to the results of characterization, the main features of NMC materials, like large pore size and abundant basic nitrogen-containing groups on the surface, should be related to the excellent adsorption property for MO.

Complete oxidation of formaldehyde at ambient temperature over supported Pt/Fe2O3 catalysts prepared by colloid-deposition method.

The catalytic properties of iron oxide supported platinum catalysts (Pt/Fe(2)O(3)), prepared by a colloid deposition route, were investigated for the complete oxidation of formaldehyde. It is found that all the Pt/Fe(2)O(3) catalysts calcined at different temperatures (200-500°C) were active for the oxidation of formaldehyde. Among them, the catalysts calcined at lower temperatures (i.e., 200 and 300°C) exhibited relatively high catalytic activity and stability, which could completely oxidize HCHO even at room temperature. Based on a variety of physical-chemical characterization results, it is proposed that the presence of suitable interaction between Pt particles and iron oxide supports, which is mainly in the form of Pt-O-Fe bonds, should play a positive role in determining the catalytic activity and stability of the supported Pt/Fe(2)O(3) catalysts.