Power & Digital Infrastructure Acquisition II Corp. (XPDBU) operates as a blank check company, or special purpose acquisition company (SPAC), formed to pursue a merger, capital stock exchange, asset acquisition, stock purchase, reorganization, or similar business combination with one or more businesses in North America's transition energy and renewable sector; it holds no significant standalone operations or products prior to such a transaction. Incorporated in 2021 and headquartered in Chicago, Illinois, the company targets opportunities in electrical power grid transition, power generation, and digital infrastructure, serving institutional and accredited investors through its publicly traded units comprising Class A ordinary shares and warrants. In March 2024, it completed a reverse merger with Montana Technologies LLC, inventor of AirJoule technology for atmospheric thermal energy conversion, dehumidification, evaporative cooling, and water harvesting; the combined entity rebranded as Montana Technologies Corporation (AIRJ), secured over $50 million in private investments from Carrier Corporation, GE Vernova, Rice Investment Group, and others to fund commercialization; and established a joint venture with GE Vernova to launch AirJoule alongside partners including BASF and CATL.