As the climate crisis becomes a part of daily life with unprecedented heat waves and cold snaps, technology to effectively remove greenhouse gases is emerging as a critical global challenge. In particular, catalytic technology that decomposes harmful gases using oxygen is a key element of eco-friendly purification. South Korean researchers have identified the principle that catalysts—which were previously vaguely thought to simply "use oxygen well"—can selectively utilize different oxygen sources depending on the reaction environment, presenting a new standard for catalyst design.