You expect China sending troops to fight for Russia? Ukraine is also China's good friend and the corner stone of China's foreign policy is non interference, we are not America. As a friend, we can cancel out western sanctions against Russia and make the west shoot themselves in the foot, arguably only China can help Russia to pull this trick.
With this?
"China's spending on Russian goods soared 60% in August from a year ago, hitting $11.2 billion, according to Chinese customs statistics, surpassing July's 49% gain."