Hydrogen Activation on Zeolite Stabilized Ni-Mo Sulfide Clusters

Area of Science:

• Catalysis
• Materials Science
• Surface Chemistry

Background:

• Molybdenum sulfide (Mo) clusters in NaY zeolite are active catalysts.
• The influence of co-catalysts on Mo sulfide cluster performance is not fully understood.

Purpose of the Study:

• To investigate the effect of nickel (Ni) incorporation on the catalytic activity of NaY-encapsulated Mo sulfide clusters.
• To elucidate the mechanism of hydrogen activation and stabilization in bimetallic Ni-Mo sulfide catalysts.

Main Methods:

• Synthesis of Ni-modified NaY zeolites via ion exchange with Ni2+.
• Deposition of Mo(CO)6 and subsequent sulfidation to form Ni-Mo sulfide clusters.
• Characterization of hydrogen binding states using spectroscopic techniques.
• Evaluation of catalytic performance in ethene hydrogenation.

Main Results:

• Bimetallic Ni-Mo sulfide clusters were successfully synthesized within NaY zeolite.
• Ni incorporation altered hydrogen binding from Mo-hydrides to include S-hydryl groups.
• The formation of S-hydryl groups was attributed to reduced electron density on Mo clusters due to Ni2+ coordination.
• Ethene hydrogenation rates were significantly higher on Ni-Mo sulfide catalysts compared to monometallic Mo sulfide catalysts.

Conclusions:

• Nickel significantly influences the catalytic properties of Mo sulfide clusters in NaY zeolite.
• The stabilization of hydrogen as sulfhydryl groups provides a novel pathway for enhanced ethene hydrogenation.
• Bimetallic Ni-Mo sulfide catalysts offer improved performance for hydrogenation reactions.