The effects of different promoters (including Sn

In

Ga

and K) on the activity

ethylene selectivity

and stability of the encapsulated Pt@silicalite-1 for ethane dehydrogenation were investigated. The dual-promoter catalysts

KPtIn@S-1 and KPtSn@S-1

exhibited high ethane initial conversions

high ethylene selectivity at 550°C

and high stability

with almost no deactivation during 30 hours on stream and the deactivation constants as low as 0.0003 and 0.0002 hour−1

respectively. Combining the characterization and performance evaluation results

it could be deduced that the introduction of Sn and In promoters plays an important role in diluting Pt

resulting in the reduced average Pt particle size. Moreover

the Sn introduced in KPtSn@S-1 led to the formation of a Si–O–Sn interaction structure between Sn and S-1 zeolite framework

resulting in the anchoring effects of Sn (II) on Pt sites. In the KPtIn@S-1 sample

the strong interaction between Pt and In also played a role in anchoring Pt species

which greatly reduced the formation of carbon deposition and inhibited the production of graphitic carbon deposits.