Bimetallic Bi‐Ni oxides over carbide supports for oxidative dehydrogenation of n‐butane: Experimental and kinetic modelling

Abstract

n‐butane oxidative dehydrogenation was studied over Bi‐Ni/TiC, Bi‐Ni/SiC, Bi‐Ni/Silicalite‐1, and unsupported Bi‐Ni catalyst. The co‐impregnation technique was followed, with fixed 0.30 and 0.20 g/g for Bi and Ni respectively. The physico‐chemical properties were measured by means of BET, XRD, CO2/NH3‐TPD, and H2‐TPR techniques. The catalytic test results revealed that bimetallic Bi‐Ni/TiC catalyst exhibited the highest n‐butane conversion of 16.6 % with dehydrogenation selectivity of 83.7 % (1,3‐butadiene and butenes selectivity of 50.7 % and 33 % respectively). As regards Bi‐Ni/TiC catalyst, the main operating parameters including O2/n‐C4H10 feed ratio, space velocity, and reaction temperature were varied. The Bi‐Ni/TiC catalyst showed adequate stability for a 10 h time on stream test. The high performance of Bi‐Ni‐O/TiC catalyst is attributed to the synergistic role of reducibility, presence of strong basic sites and weak acidic sites, and an increased metal species dispersion over the TiC support. A kinetic study of n‐butane oxidative dehydrogenation was carried out. The apparent activation energy for formation of butadiene was estimated to be the lowest (15 kJ/mol), while the highest activation energy (105 kJ/mol) is required for the undesirable cracking reaction.

Intelligent chemometric modelling of Al2O3 supported mixed metal oxide catalysts for oxidative dehydrogenation of n-butane using simple features

“…Developing selective and industrially relevant catalysts for ODHB to C4 olefins while minimizing the formation of unwanted by-products such as carbon oxides (CO x ) and coke remains a main challenge. Several catalysts have been explored by researchers for ODHB; 5,[15][16][17][18] however, even the high activity that favours the yield of dehydrogenation products only gives low selectivity to C4 olefins.…”