Travelling to Vietnam (HCMC) via Peking

Hi..I am a South African citizen and my partner is rom Germany. We will both be flying to HCMC via Peking, with about 10 hours waiting time in Peking. I would like ot find out if any of us need a transit visa during this time. Does the route, in the ariport, to the Vietnam flight go through immigration where we could be required to show visas for China. Thanking you in advance.