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Pd/g-C3N4 with d–π interaction between Pd NPs and g-C3N4 with a π-conjugated system shows high catalytic activity in the dehydrogenation of FA.

A series of titanate nanotube-supported metal catalysts (M/TNTs, M = Rh, Au orAu–Rh) were facilely synthesized. The effects of different Au contents, reduction processes and sequence of loading metals on their catalytic performances in the hydroformylation of vinyl acetate were comparatively investigated. The results showed that some Au and Rh formed bimetallic particles. Furthermore, the presence of Au in catalysts could significantly improve the selectivity of reaction for aldehydes. Compared with the monometallic catalysts (Rh0.33/TNTs-1 and Au0.49/TNTs-2), the resultant bimetallic catalysts exhibited significantly higher selectivity for aldehydes as well as higher TOF values in the hydroformylation of vinyl acetate. Among them, Au0.52/Rh0.32/TNTs-12 displayed the best catalytic performance. The corresponding selectivity for aldehydes was as high as 88.67%and the turnover frequency (TOF) reached up to 3500 h−1. In addition, for the reduction of Rh3+ and Au3+ ions, the photo-reduction and ethanol-reduction were the optimal techniques under the present conditions, respectively.

The TiO2-based nanotubes (TNTs, B–TNTs) of different surface acidities and their supported Rh catalysts were designed and synthesized. The catalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectrometer (XPS), tempera–ture–programmed desorption of ammonia (NH3–TPD), atomic emission spectrometer (ICP), and Brunauer–Emmett–Tellerv (BET) surface-area analyzers. Images of SEM and TEM showed that the boron-decorated TiO2 nanotubes (B–TNTs) had a perfect multiwalled tubular structure; their length was up to hundreds of nanometers and inner diameter was about 7 nm. The results of NH3-TPD analyses showed that B–TNTs had a stronger acid site compared with TNTs. For Rh/TNTs and Rh/B–TNTs, Rh nanoparticles highly dispersed on B–TNTs were about 2.79 nm in average diameter and much smaller than those on TNTs, which were about 4.94 nm. The catalytic performances of catalysts for the hydroformylation of 2-methyl-3-butennitrile (2M3BN) were also evaluated, and results showed that the existence of B in Rh/B–TNTs had a great influence on the catalytic performance of the catalysts. The Rh/B–TNTs displayed higher catalytic activity, selectivity for aldehydes, and stability than the Rh/TNTs.

Hydroxyapatite (HA) nanopeanut, hierarchical nanorods covered with nanopits on surface, was successfully synthesized via a novel ethanol induced and stabilized route. Ca(NO 3 ) 2 , H 3 PO 4 , and NaOH were used as calcium source, phosphorus source, and pH adjusting agent, respectively. X-ray diffraction analysis showed that hierarchical nanorods are well crystallized and present a pure hexagonal Ca 10 (PO 4 ) 6 (OH) 2 . Transmission electron microscopy (TEM) exhibited that the nanorods are of 50-210 nm in length and 22-52 nm in width. The nanopits of 3-12 nm in diameter in the surface were also confirmed and calculated by nitrogen adsorption/desorption isotherms, which is well consistent with TEM observation. Ethanol as the sole functional organic molecule played the roles of improving the HA crystallization, inducing the nucleation and growth of HA nanorods, as well as inducing and stablizing the nanopits in surface. The ethanol-assisted synthesis mechanism of HA nanopeanut was proposed and discussed in thermodynamics. This novel ethanol-assisted route is green, facile, efficient, low-cost, and surfactant-free and may be useful for the synthesis of other hierarchical materials.W. Zhang-contributing editor Manuscript No. 36254.