United Press International: U.S. scientists say dual catalysts might turn carbon dioxide and water vapor into methane and other hydrocarbons using titania nanotubes and solar power. Burning fossil fuels such as oil, gas and coal release large amounts of carbon dioxide into the Earth’s atmosphere. But Pennsylvania State University researchers said rather than contributing to global climate change, producers could convert the CO2 into a wide variety of hydrocarbons. “Recycling of carbon dioxide via …