This paper provides a systemic study of China's policy and legal responses to security-related actions and disputes in the international trade regime. It starts with a brief review of the law and practices relating to the security exceptions under the World Trade Organization to provide an important context for understanding the recent developments of China's approaches to national security. Based on a detailed discussion of China's approaches at international and domestic levels, we argue that China's security strategy has been shifting from being defensive to proactive: internationally by seeking to influence the development of trade rules and practices, and domestically by expanding national security to cover a wide spectrum of economic security interests and developing a comprehensive regulatory framework to protect such interests. The way in which major trading nations are taking the law into their own hands, based on ever-expanding security interests, does not bode well for the future of the multilateral trading system. There is a pressing need for collective action by all governments involved to re-design security-related rules and exceptions to confine the use of security measures to agreed parameters.

A series of MnOx–CeO2 binary oxide catalysts were synthesized by polyvinylpyrrolidone -assisted supercritical antisolvent precipitation and the effects of the manganese (Mn)/cerium (Ce) molar ratio and calcination temperature on the structure and properties of MnOx–CeO2 were investigated. A solid solution was obtained at each experimental condition and the highest surface area of 107.6 m2/g was obtained at the Mn/Ce molar ratio of 3:5 and the calcination temperature of 400 °C. Low-temperature selective catalytic reduction of emissions of nitrogen oxides, namely NO, NO2, and N2O (deNOx) with ammonia (NH3) to convert them into nitrogen and water, was used as model reaction to evaluate MnOx–CeO2 catalytic performance. It is found that the activity first increased and then decreased with increasing Mn content and decreased with increasing calcination temperature. The highest catalytic activity (93.3% NO conversion and 100% N2 selectivity) was obtained at the Mn/Ce molar ratio of 1/1 and the calcination temperature of 400 °C, which was attributed to the combination of high surface area and high redox performance of the catalyst.