Issue
Korean Chemical Engineering Research,
Vol.58, No.4, 658-664, 2020
Blocking of Zeolite Pore by Loading Ni-Pt Nanoparticles for Maximization of Isomerization Selectivity
Zeolite HY is wet impregnated with Ni (0.1, 0.3, 0.4, 0.5 wt%), Pt (0.1 wt%) and reduced in presence of hydrogen to form nanosized particles of Ni and Pt. All the catalysts were characterized by XRD, TEM, ESCA, NH3-TPD, Pyridine adsorbed FT-IR and BET. Characterization results confirm that the Ni and Pt fractions effectively rehabilitated the physio-chemical properties of the zeolite HY catalysts. Further, all the reduced catalyst were screened with hydroisomerization of m-xylene at LHSV = 2.0 h-1 in the temperature range 250-400 °C in steps of 50 °C in hydrogen atmosphere (20 ml/g).The addition of Ni to Pt catalyst increases hydroisomerization conversion, as well as maximizes p-xylene selectivity by restricting the pore size. The increasing trend in activity continues up to 0.3 wt% of Ni and 0.1 wt% Pt addition over zeolite HY. The increasing addition of Ni increases the total number of active metallic sites to exposed, which increases the metallic sites/acid sites ratio towards the optimum value for these reactions by better balance of synergic effect for stable activity. The rate of deactivation is pronounced on monometallic catalysts. The results confirm the threshold Ni addition is highly suitable for hydroisomerization reaction for product selectivity over Ni-Pt bimetallic/support catalysts.
[References]
  1. Briand LC, Daly J, Wust J, IEEE Transactions on Software Engineering, 25(1), 91-121(1999).
  2. Breck DW, John Wiley and Sons, New York(1974).
  3. Weisz PB, Frilette VJ, J. Phys. Chem., 64, 382, 1960
  4. Sreedharan R, Bhatia S, Chem. Eng. J., 36, 101, 1987
  5. Canizares P, de Lucas A, Dorado F, Duran A, Asencio I, Appl. Catal. A: Gen., 169(1), 137, 1998
  6. Ostard J, Kustov L, Poeppelmeier KR, Sachtler WMH, J. Catal., 133, 342, 1992
  7. Filho JGP, Schmal M, Monteiro JL, Catal. Today, 5(4), 503, 1989
  8. Chaudhari K, Das TK, Chandwadhkar AJ, Sivasankar S, J. Catal., 189, 81, 1999
  9. Arribas MA, Marquez F, Martinez A, J. Catal., 190(2), 309, 2000
  10. Minchev CH, Knazirev V, Kosova L, Pencev V, Grunsser W, Schimidt F, Heyden, London, 335-340(1980).
  11. Bhavani GA, Karthikeyan D, Lingappan N, Rao SA, Indian J. of Pure and Applied Physics, 44, 177-182(2006).
  12. Babu GP, Kulkarni SB, Ratnasamy P, J. Catal., 79, 215, 1983
  13. Boskovic G, Micic R, Pavlovic P, Putanov P, Catal. Today, 65(2-4), 123, 2001
  14. Jao RM, Lin TB, Chang JR, J. Catal., 161(1), 222, 1996