Activity of Ni/CeO2 catalyst for gasification of phenol in supercritical water. (11th October 2018)

• Record Type: Journal Article
• Authors: Li, Bin; Zhang, Baohua; Guan, Qingqing; Chen, Shanshuai; Ning, Ping
• Is Part Of: International journal of hydrogen energy. Volume 43:Number 41(2018)
• Page Start: 19010
• Page End: 19018
• Publication Date: 2018-10-11
• Subjects: Phenol -- Gasification -- Supercritical water -- Ni/CeO2; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2018.08.105
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: An effective Ni/CeO2 catalyst prepared by the polyol reduction method for degrading phenol into CH4, H2 and CO2 in supercritical water (SCW) was developed. About 80% carbon gasification efficiency can be achieved at 525 °C and 60 min with 5 wt% phenol, 0.098 kg/m 3 water density and 0.5 g Ni/CeO2 /g phenol catalyst, forming CH4 and H2 as the main gaseous products. Comparison study indicated that the efficiency of present Ni/CeO2 catalyst was about 20% higher than that of a commercial catalyst, i.e., Ni/SiO2 Al2 O3 from Sigma-Aldrich with 65 wt%Ni, at a reaction conditions of 500 °C and 30 min. The characterization analyses of BET, TPR, XRD, XPS and TEM indicated that there was a NiCe alloy formed in Ni/CeO2, which could be important to enhance the activities of the carbon gasification efficiencies and gas yields. A kinetic modelings were conducted and the results showed that the lnA and the activation energy (Ea) of gasification were 7.1 ± 0.5 and 58.1 ± 3.2 kJ/mol for the gaseous product, and were 2.6 ± 0.9 and Ea is 36.6 ± 5.6 kJ/mol for the char formation, respectively. The present Ni-based-metal Ni/CeO2 catalyst is cheaper and has a potential application for the gasification to convert phenol into gases fuels in SCW process. Highlights: Ni/CeO2 catalyst prepared by the polyol reduction method with the presence of alloys. Ni/CeO2 catalyst firstly applied for phenol gasification in SCW and performed well. CH4 is the major selected gas product from phenol gasification using Ni/CeO2 in SCW. The efficiency of Ni/CeO2 was about 20% higher than that of the commercial catalyst.