That's a tough question, because pornography can be very addictive. Like other addictions, quite often no amount of arguing, debating, pleading, and so on can sway the addict. If you can calmly help him see that there is a problem, then change is possible, but he has to want to stop his addiction. I have heard of some wives "ambushing" their husband when he least expects it with a handjob or b*l*o*w*j*o*b, so that he temporarily, at least, is not interested in porn, but that is something that you would have to want to do.
If you can offer better pleasure than porno. This could be in the form of exercises. If he is lured to do some exercises, he may not be keen to watch porno and turn to normal sex. Male deer exercise, kegel exercise, Sat kriya, Anal peripheral prostate massage( it can serve is masturbating if he like this anal massage) You may help him to do male deer exercise. You may kegel him during intercourse. This will give him extra pleasure by having different sensation. Let hi do some research convincing him that he would get more pleasure with actual sex after exercises.Of course I know the difficulty you face in convincing him to do exercises.
How about he just stops watching porn and jerking off so his wife even has a chance to please him. There's nothing she can do this is his issue. Stand firm and don't back down. Porn addiction is destroying people's lives.