Blending is essential in catalysis for several reasons: 1. Enhanced Activity: Combining different catalysts can lead to higher activity due to synergistic effects. 2. Improved Selectivity: Blending can improve the selectivity of a catalyst towards a desired product. 3. Stability: Blending can enhance the thermal and mechanical stability of catalysts. 4. Cost Efficiency: It can reduce the cost by using less of expensive materials and more of cheaper, supportive ones.