If you're looking for a meeting place or a good stop around ½ or halfway between Duiven and Moers, you can try Wesel, Germany, which is about half an hour southeast of Duiven, or about half an hour north of Moers.
Another possible place to stop near the midpoint is Hamminkeln.
About ¼ or a fourth of the way, you can stop at Emmerich, Germany. This is about 14 minutes southeast of Duiven.
About ⅓ or a third of the way, you can stop at Isselburg, Germany. This is about half an hour southeast of Duiven.
About ⅔ or two thirds of the way, you can stop at Hunxe, Germany. This is almost an hour southeast of Duiven, or about half an hour northeast of Moers.
If you drive straight through without stopping at all, the total distance is 106 km. The distances shown above don't include local roads to get into each town, so if you're planning a long road trip, make sure you factor in traffic and road conditions, rest stop breaks, and interesting detours along the way. If you're in a rush, you can do the trip with zero stops, and your total travel time would be around 1 hour, 7 minutes.