Hydrogen Spillover-Accelerated Selective Hydrogenation on WO₃ with ppm-Level Pd

Area of Science:

• Catalysis
• Materials Science
• Chemical Engineering

Background:

• Hydrogen spillover is crucial for designing dual-active site catalysts.
• Limited understanding exists regarding the link between hydrogen spillover capacity and hydrogenation performance.

Purpose of the Study:

• To demonstrate hydrogen spillover-dependent selective hydrogenation using palladium on tungsten oxide (Pd/WO3) catalysts.
• To investigate the role of WO3 support properties in enhancing hydrogen spillover and catalytic activity.

Main Methods:

• Fabrication of ppm-level palladium on WO3 (PdHD/WO3) catalysts.
• Characterization of WO3 supports with hexagonal phase and oxygen defects.
• Evaluation of catalytic performance in the hydrogenation of 4-chloronitrobenzene.

Main Results:

• WO3 supports with hexagonal phase and optimal oxygen defects enhanced hydrogen spillover capacity.
• PdHD/WO3 catalysts achieved a high turnover frequency (TOF) of 47,488 h⁻¹, 33 times higher than Pd/C.
• Achieved >99.9% selectivity for 4-chloroaniline due to spillover-enhanced adsorption on WO3 oxygen vacancies.

Conclusions:

• Hydrogen spillover is an effective strategy for developing highly active and selective hydrogenation catalysts.
• Cost-effective nanocatalysts with low palladium loading can be fabricated using this approach.
• Optimized WO3 supports are key to maximizing hydrogen spillover and catalytic efficiency.