Environmental pollution and energy storage are two major challenges faced by human beings. The magnitude of them is ever-increasing due to rapid pace of urbanization and industrialization. In view of this, to achieve green environment and provide clean energy for human beings are pivotal for sustainability. The catalysis technology plays dominant role in addressing these issues. The nano/microstructured catalyst with intriguing physical and chemical properties could offer numerous opportunities to realize environmental sustainability and clean energy production. In the past two decades, great advances have been made on the design, synthesis and mechanistic understanding of typical catalysts for environmental and energetic applications. These new catalysts in various fashions can be classified into three main types, thermal catalysis, photocatalysis and electro catalysis. In some cases, two types can be combined together, such as photoelectrocatalysis and photothermal catalysis, to achieve higher catalysis efficiency. The features of catalysts can be further tailored to allow for enhanced catalytic performance in pollutant degradation and energy conversion. Advanced in situ techniques have been applied to explore and reveal the catalytic mechanisms.