Well down in the article it is noted that the process generates CO2 which must then be captured if this is going to be emission free. Industrial scale carbon dioxide capture is going nowhere fast. No matter how sexy the means of its production, it’s still just plain old CO2.
Although, I’m not a believer about CO2 being a pollutant, they may be able to capture it and use it for other purposes.
It’s also about ration. How much CO2 is produced vs how much hydrogen. If enough hydrogen is produced, compared to CO2, it may be worth the exchange.