The application of Pd in three-way catalyst represents a significant technology breakthrough for the removal of pollutants from gasoline powered vehicle exhaust gas. Pd shows superior catalytic activity for hydrocarbon (HCs) oxidation and thermal stability to the conventional Pt/Rh catalyst. However, Pd catalysts are more susceptible to chemical poisoning. This work summarizes the progress of the Pd-based three-way catalyst and its related technologies. The state of Pd in the reaction, the support and oxygen storage material, the promoters, and preparation methods on the catalytic performance are reviewed. The process and catalyst configurations, e.g., close-couple (CCC), dual bricks, layered, and zone-coated catalysts, are described and compared. The advances in the understanding of the reaction and deactivation mechanisms in the three-way catalysis systems are also discussed.

The dehydration of D‐fructose and glucose has been studied with acidic ionic liquids as catalysts. A series of Brønsted‐acidic ionic liquids has been synthesized and tested in the dehydration of D‐fructose. The results showed that N‐methyl‐2‐pyrrolidonium methyl sulfonate [NMP]⁺[CH₃SO₃]⁻ and N‐methyl‐2‐pyrrolidonium hydrogen sulfate [NMP]⁺[HSO₄]⁻ have high catalytic activity. Highly efficient and selective dehydration of D‐fructose to 5‐hydroxymethylfurfural (HMF) was achieved in dimethyl sulfoxide (DMSO) under mild conditions. For example, a 72.3 % yield of HMF with 87.2 % selectivity were obtained for 2 h at 90 °C in the presence of 7.5 mol % [NMP]⁺[CH₃SO₃]⁻. The effects of the reaction temperature, time, and solvent were investigated in detail. The catalyst and solvent can be recycled for the dehydration of D‐fructose. The Hammett method was used to determine the acidities of these ionic liquids, which indicated that the acidity and molecular structure have strong effects on the catalytic activity of ionic liquids. Based on the experimental results, a possible reaction mechanism for the dehydration of D‐fructose is proposed.