Catalytic wet air oxidation of phenol over ultrasound-assisted synthesized Ni/CeO2–ZrO2 nanocatalyst used in wastewater treatment

Abstract

Non-noble metal Ni with different loadings was coated on precipitated CeO 2 -ZrO 2 support by the sonochemistry method and examined for catalytic wet air oxidation of phenol. The structure of the nanocatalysts was determined by BET, FESEM, XRD, and FTIR analyses. The results showed non-uniform morphology of the nanocatalyst at lower Ni contents changed to homogenous morphology with spherical nano particles at higher Ni contents. While the size of NiO crystals remained constant with rising Ni content, the crystallinity of NiO significantly increased. If the crystallinity of NiO was 100% in 20% wt Ni/CeO 2 -ZrO 2 , the crystallinity of NiO in 5% wt Ni was found to be 41.13%. The average particle size in Ni(15%)/CeO 2 -ZrO 2 was 77 nm in which 85.71% of particle diameters were less than 100 nm. Catalytic wet air oxidation of phenol with different Ni loadings indicated improvement of phenol destruction at higher amounts of active phase. Removal of phenol increased with increasing catalyst loading from 4 to 9.0 g/l but further increase to 10 g/l declined the catalyst reactivity. ª 2014 The Authors. Production and hosting by Elsevier B.V. on behalf of King Saud University. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/3.0/).

Treatment of phenol by catalytic wet air oxidation: a comparative study of copper and nickel supported on γ-alumina, ceria and γ-alumina–ceria

“… 40–44 Ni has been used mainly for steam reforming reactions, and poorly for oxidation reactions. 45–49 However, to our knowledge using Ni/Al 2 O 3 , NiCeO 2 and Ni/Al 2 O 3 –CeO 2 catalysts with nano characteristics for the catalytic wet air oxidation of phenol in milder conditions has not been reported in the literature, so there was enthusiasm to investigate this nano structured system.…”

Chemical and Structural Changes by Gold Addition Using Recharge Method in NiW/Al2O3-CeO2-TiO2 Nanomaterials

“…Its ability to store and release oxygen due to the effective redox Ce 4+ /Ce 3+ sites that enable the exchange of oxygen via oxygen vacancy significantly increases the performance of catalytic systems and suppresses the deactivation of catalysts under rigorous reaction conditions [ 57 , 58 ]. For the degradation of refractory organic compounds (ROCs), it has been reported that the oxygen storage capacity (OSC) and the redox properties of ceria should be increased by the introduction of other transition and nontransition metal ions; therefore, many ceria-based catalysts have been developed, such as CeO 2 -ZrO 2 [ 57 , 58 , 59 , 60 , 61 ], CeO 2 -TiO 2 [ 62 , 63 , 64 ], CeO 2 -WO 3 [ 65 ], CeO 2 /Al 2 O 3 [ 66 , 67 ] and CeO 2 -SiO 2 [ 68 , 69 , 70 ]. Besides, the species Ti 3+ for the TiO 2 support is related to oxygen vacancies as a result of lattice distortion or surface defects [ 71 ].…”

Optimizing CO2 methanation: effect of surface basicity and active phase reducibility on Ni-based catalysts

“…The bands between 400 and 500 cm −1 correspond to Ni-O stretching 73 and Ni-O-Ni bond. 74 The CO 2 methanation performance of the reduced samples is evaluated at 400 °C (Fig. 6).…”