Carbon nanotube (CNTs) and activated carbon (AC) supported Pd and Ni catalysts were prepared for the (in situ) hydrogenation of phenol to cyclohexanone and cyclohexanol. The hydrophobic/hydrophilic properties of the catalysts were tailored by pretreating the carbonaceous support with HNO3 at various conditions and characterized by X-ray photoelectron spectroscopy (XPS), temperature-programmed desorption (TPD), and transmission electron microscopy (TEM). The catalytic results suggested that Pd and Ni supported on CNTs show significantly higher activity than that supported on ACs. Pretreating the CNTs with HNO3 increases the local hydrophilicity of the active phase (by introducing oxygenated groups), which result in an increase in the cyclohexanone selectivity and strongly decrease the phenol conversion. The first-principles density functional theory calculation suggested that the adsorption/desorption behaviors of phenol, methanol, H2O, and cyclohexanone on the catalysts might be influenced highly by the hydrophobic/hydrophilic properties. The hydrophilic catalysts show high selectivity in cyclohexanone by lower conversion in phenol or vice versa.
A series of lanthanum-promoted Pd/Al 2 O 3 catalysts (Pd/La x -Al 2 O 3 ), for the liquid phase in situ hydrogenation of phenol into cyclohexanone, was prepared by the incipient wetness impregnation method. Addition of lanthanum to Pd/Al 2 O 3 enhances the TOF of the catalyst for the liquid phase in situ hydrogenation of phenol significantly. The conversion of phenol is highly dependent upon the atomic ratio of La/Pd, but the presence of lanthanum has little effect on the selectivity of cyclohexanone. The selectivity of cyclohexanone in the liquid phase in situ hydrogenation of phenol over the Pd/La x -Al 2 O 3 catalyst is as high as 98%, which is quite higher than the hydrogenation using H 2 (67.4%). Results from BET, EDS, CO chemosorption, XRD and H 2 -TPR suggest that the presence of suitable amounts of lanthanum improves the Pd dispersion on the support. The peak temperature for the reduction of PdO in the H 2 -TPR moves to higher in the presence of lanthanum. Additionally, the Pd particles could adhere to the lanthanum rather than the Al 2 O 3 .
A resource recycling technique of hydrogen production from the catalytic degradation of organics in wastewater by aqueous phase reforming (APR) has been proposed. It is worthy of noting that this technique may be a potential way for the purification of refractory and highly toxic organics in water for hydrogen production. Hazardous organics (such as phenol, aniline, nitrobenzene, tetrahydrofuran (THF), toluene, N,N-dimethylformamide (DMF) and cyclohexanol) in water could be completely degraded into H 2 and CO 2 with high selectivity over Raney Ni, and Sn-modified Raney Ni (Sn-Raney-Ni) or Pd/C catalyst under mild conditions. The experimental results operated in tubular and autoclave reactors, indicated that the degradation degree of organics and H 2 selectivity could reach 100% under the optimal reaction conditions. The Sn-Raney-Ni (Sn/Ni=0.06) and Pd/C catalysts show better catalytic performances than the Raney Ni catalyst for the degradation of organics in water into H 2 and CO 2 by the aqueous phase reforming process. organic wastewater, catalytic degradation, hydrogen production, resource recycling, aqueous phase reforming Protection of water environment or the purification treatment of pollutants in water has become one of the most important work with great challenges in ecological protection nowadays. The organic wastewaters from the industrial production processes of dyes, pharmaceuticals, pesticides, leather, petrochemicals and food are of complex chemical composition, poor biodegrability, thus polluting water environment heavily and also weakening the fecundity of aquatic organisms seriously [1,2] . Currently, the purification technique of organic wastewaters includes biological degradation (such as aerobic organisms, anaerobic organisms, biological film, biological enzyme and fermentation engineering) [3] , chemical treatment (including incineration, fenton oxidation [4] , ozone oxidation [5] , electrochemical oxidation [6] , wet catalytic oxidation [7] , photocatalytic oxidation [8] , supercritical water oxidation, [9] etc.), physical-chemical coupling and physicochemical-biochemical coupling, [1] etc. Biological degradation methods for the purification treatment of organic wastewater are of low cost and free from secondary pollution [1] , but it is difficult to achieve the complete degradation of refractory and high toxic organics in water. Chemical methods are usually used for the purification treatment of hazardous organics in water effectively, but the rigorous conditions and strong oxidants are inevitably needed. The physical-chemical and physicochemical-biochemical coupling methods have been regarded as the cheap ways of degrading organics in water into H 2 O and CO 2 completely [1] . How-
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