The ZDDP kills Catalytic converters is just another example of " Internet misinformation " or " Partial information ". Catalytic converters are a consumable product. Just like Brake pads or Clutches. Thye have a finite Lifespan. Alway have... alway will have.
ZDDP does not " Kill " Catalytic converters. Cars have had Catalytic converters since the Mid 1970's and the oils back then had a hell of a lot more ZDDP in them back then. They lasted fine back then and still do.
The only reason for the reduction in ZDDP in Motor oils is because the EPA upped the testing standard for Catalytics from 100,000 miles to 150,000 miles in the mid 2000's.
Now one of the main materials of a Catalytic converter is Platinum. Platinum is freakin' expensive. Almost equal to the cost of Gold per once. Now ZDDP does slowly, very slowly degrade the performance of the Platinum Catalyst. But it takes a super long time and Manufacturers used just enough Platinum to last 100,000 miles and still pass the EPA test.
But when the EPA decided to raise the test standards to 150,000 miles . No problem, the engineers could meet that standard. They just had to use more Platinum in the Honeycomb Matrix. So this was just an engineering problem.... and then the " Bean Counters " got involve. They didn't want to fork out more money for added Platinum. And studies had shown that if you reduced the amount of ZDDP in the oils, then you could meet the new tougher EPA test with the same Catalytic converters and amounts of Platinum in them.
Note: ZDDP's main function is to reduce metal to metal contact in extreme load situations. It is a VERY effective extreme pressure agent. The interface between a flat tappet lifter and camsahft, or sliding finger follower style Valvetrain is the highest load pressure point in an engine.
Since all of the BIg 3 manufactures had been using Roller Lifter or Roller follower Valve Trains since the late 80's to early 90's, this sounded like a great idea to the Bean Counters. Make an oil with less ZDDP and problem solved. The oil makers were on board with this as they could save a couple of pennies in additive amounts of ZDDP in each bottle of oil.
Only 1 company objected. GM. They did not agree with the amount of ZDDP reduction that the oil companies and EPA had proposed. They were worried about, older engines... that still used Flat Tappet Cams. Like those in GM SBC.BBC,, and Pontiac and Buick engines still being used buy Vintage car owners, hot rodders and Racers. And also in older trucks, generators and agriculture for pumping stations etc They actually proposed a les strict Oil standard in ZDDP reduction , that would be compatible with older flat tappet Cams ( and finger followers ) and could meet the the new 150,000 mile Catalytic tests.... with only a slight increase in Platinum amount required, compared to the Current SG/SH oils. But this proposal was shot down by the EPA and other manufacturers.
Vintage cars, old vehicles and Lord forbid " Racers ???? F**k them. Let them all buy new Jelly Bean cars. They're all a bunch of degenerate heathens.
And this in the mid-2000's, you started seeing the " Great Camshaft Meltdown " with horror stories of Hot Rods and High Performance engines grinding their Camshafts into mush. Problem was exacerbated with High Lift cams and stiffer Valve springs. But fear not. The Oil companies came back with a solution. They would introduce new " Specialty Oils " , that did not have to the new Energy Star ( SM/SN API rating ) . So they basically introduced an old formula oil, then slapped some fancy stickers on it and called it " Hot Rod " oils. And of course they charged double the money, because this was " Special Oil "...... and they had the Hot Rodders, Muscle Car and Vintage enthusiasts by the balls.
PT Barnum would have been proud...
So in short... if you have a pre 2006 car, older higher Zinc oils won't " Kill " your Catalytic converter. At least not very quickly.
If you have a later model car and are concerned about maintaining the Emissions warranty for 150,000 miles ... then you may want to use a new Energy Star rated SM/SN oil. Of course if you do ANY modifications to the valve train. All bets are off.
Oh, and if you have a new car with Direct Fuel Injection? Good Luck. Better find out how the High Pressure Injection Pump ( Up to 1,660 PSI ) is made. The bosch systems ( Audi/VW. BMW, Mercedes Porsche and others ) use a Bucket lifter in the High Pressure pump. Guess what... they are wearing out in as little as 20,000 miles. Even with numerous recalls on DI Injection pumps and " Diamond Like Coatings " being spayed on the buckets,. All because the new oils are SH*TE. It's a HUGE industry problem. Especially in Europe on the Autobahns. Higher speeds, higher engine temps, oil thins out.... buh bye $2,000 to $3,000 dollar injection pump.
Some of the Japanese manufactures were smarter. They used Roller Tipped actuators to operate the High Pressure pump. No issues with reduced ZDDP. FWIW.
BTW, all of this information is available in SAE White Papers and Technical articles like Engine Tech and Race Car engineering. Also covered on dedicated sites such as " Bob Is The Oil Guy ", Despite the rather strange name, BITOG is one of THE best sites for accurate lubrication information. Where actual Chemical, Mechanical and Petroleum engineers contribute regularly. an Laboratory Testing results are abundant. Well worth a visit and a long read.
https://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=cfrm